des guide 1 roadside signs

Design GuideDesign Guideforfor

Roadside SignsRoadside Signs

Prepared by:Traffic Engineering & Road Safety BranchTraffic & Road Use Management Division

Design Design GuideGuideforfor

Roadside SignsRoadside Signs

Edition 1, Rev. 1, February 2001

Registration Number: 80.255

Issued by the

Department of Main Roads

Traffic & Road Use Management Division

For document control enquiries contact: Document Control OfficerProject Management Services DivisionPO Box 975Spring Hill Qld 4004Phone: (07) 3834 2035Facsimile: (07) 3834 2899

For document content enquiries contact: Traffic & Road Use Management DivisionGPO Box 1412Brisbane Qld 4001Phone: (07) 3834 2443Facsimile: (07) 3834 2201

© The State of Queensland Department of Main Roads, 2001

Users of this Guide are reminded that Copyright in this Guide subsists with the QueenslandDepartment of Main Roads, and should note that except where the Copyright Act allowsand except where provided for below, this Guide may not be reproduced, stored in aretrieval system in any form or transmitted by any means without prior permission in writingfrom the Department of Main Roads.

Every effort has been made to ensure that the information contained in this Guide is correctat the time of printing. Due to continual developments in new standards and best practice,users should ensure that the information is up to date before it is applied. Errors orsuggestions for change should be reported using the Document Content Change ControlForm. Suggestions for the inclusion of new information are particularly welcome.

The standards used for wind loadings apply only to roadside signs which can collapsewithout damage to pedestrians or other parties. Design charts and tables should not beused in isolation from the design restraints and text of the Guide. Reproduction of singledesign charts is considered to be a serious matter as this is a total package where thedesigner is required to assess the risk level appropriate to the site conditions.

Traffic & Road Use Management DivisionQueensland Department of Main RoadsGPO Box 1412Brisbane QLD 4001

Copyright Design Guide for Roadside Signs

ii Issue: February 2001

Guide RegistrationInstructions for Design Guide for Roadside Signs

ORIGINAL HOLDER

Please acknowledge receipt of this Guide by photocopying, completing and forwarding theHolder Details Form. Queensland Department of Main Roads and Queensland Transportholders should note that, for document control purposes, this Guide should be registered toa position, not an individual.

SUBSEQUENT HOLDER(S)

Subsequent holders should advise the Document Control Officer as soon as the Guide isobtained. The Holder Details Form should be returned with updated holder details.

CHANGE OF ADDRESS

Should a Guide holder change address, please forward an updated Holder Details Form tothe Document Control Officer.

CHANGE OF POSITION

Should a Guide holder change position and no longer require this Guide, it should be leftfor the person filling the subsequent vacancy. If continued reference to this document isrequired (in the original holder�s new position), please forward a Holder Details Form to theDocument Control Officer.

AMENDMENTS

Advice of future amendments will be forwarded according to the distribution register heldby the Document Control Officer. Holders who fail to register will loose the benefits ofawareness of current �best practice�. Prompt notification of change of address will ensurethat users are advised of amendments as they are issued.

Design Guide for Roadside Signs Registration

Issue: February 2001 iii

Design Guide for Roadside Signs

HOLDER DETAILS FORMPhotocopy, complete and return to Document Control Officer to be informed of any updates or to requestmodification to Guide content.

� Change of address (photocopy, tick the box, complete with new details and return to Document Control Officer)

� Internal Mail � Post EnquiriesAttention: Document Control Officer Department of Main Roads Telephone:Project Management Services Project Management Services (07) 3834 20352nd Floor PO Box 975 Facsimile:1 Dickens St, SPRING HILL SPRING HILL, QLD 4004 (07) 3834 2899

Document Details:Title: .........................................................................................................................................................

Registration Number: 80.255 Copy Number:................................................(The copy number allocated to your Guide will besent to you when you return this form)

Holder Details:Surname (Mr/Mrs/Miss/Ms): ................................................Given Name: .....................................

Mailing Address:.....................................................................................................................................

..................................................................................................................................................................

Internal Holder External Holder

� Queensland Transport � Personally held

� Main Roads � Held by Organisation, Association etc. (eg library)

(Note: Internal holders should register this Guide Organisation Name: ........................................................

to a position) ........................................................................................

Position Name:................................................................. Position Name:................................................................

Division/District: ............................................................... Division/District: ..............................................................

Branch/Section: ............................................................... Branch/Section: ..............................................................

District Number: ............................................................... ........................................................................................

Request for Modification to Guide Content:

...............................................................................................................................................................................

...............................................................................................................................................................................

...............................................................................................................................................................................Please attach further information (if required)

Review (by Traffic Engineering & Road Safety Branch)

Comment/Action: .................................................................................................................................................................................................................................................................................................................................

...............................................................................................................................................................................

...............................................................................................................................................................................

Holder advised: .....................................................................................................................................................

Signature .............................................................. Date .....................................................................

Registration Design Guide for Roadside Signs

iv Issue: February 2001


Traffic Engineering Section � Traffic & Road Use ManagementDivision

The Traffic Engineering Section of Traffic & Road Use Management Division develops andprovides appropriate guidance in relation to traffic engineering standards in Queensland. It alsoprovides technical support, training and a diverse traffic engineering consultancy service.Following the commercialisation of the Traffic & Road Use Management Division of Main Roads,these services are provided on a full commercial basis to both the public and private sectors.

Major functions include:-

� the provision of full traffic engineering services including traffic studies and impactassessment, design of sign and pavement marking layout for design schemes,development and support of traffic management systems.

� investigation of matters relating to traffic control devices and traffic operations inconjunction with other research organisations such as Australian Road Research Board,AUSTROADS and other State Road Authorities.

� research and develop standards and guidelines to increase safety of all road usersthrough investigations of speed zoning, roadside hazards, road geometry, intersectiontreatments and information systems.

� monitoring and evaluation of traffic safety programmes and standards.

� liaison within the Department of Main Roads in Queensland, Local Governments,Government Departments and the private sector.

Accredited training can be provided in a number of areas including:

� Roadworks signing

� Introductory level traffic engineering

� Pavement marking.

The Manual of Uniform Traffic Control Devices, Guide to Pavement Markings, Design Guidefor Roadside Signs and the Traffic Engineering Manual are some of the more well knownpublications developed by the Traffic Engineering Section.

Further information on the capabilities of Traffic Engineering Section may be obtained bycontacting the Principal Engineer (Traffic).

Design Guide for Roadside Signs Traffic Engineering Section

Issue: February 2001 v


vi Issue: February 2001

This page is purposelyleft blank

Preface

This edition of the guide, Edition 1, Revision 1, Design Guide or Roadside Signs (2001)replaces all previous issues.

Sign Design On-Line (Release 2) has been superseded by a new computer design aidcalled �TraSiS (Traffic Sign Structures) version 2.0�. This new software programme furthersimplifies the support design task. For further details, refer to Appendix A.

Principal variations:

The principal variations from the original Design Guide for Roadside Signs are as follows:

1. Additional sign details

Additional sign details have been catered for in this guide and include the following:

(i) Truss Supports

Truss supports have been developed from the prototypes first erected by GympieDistrict. These trusses have been further rationalised and bracing developed toaccommodate larger signs.

(ii) Wind Regions

The Guide now includes Regions A, B, C and D to cater for all of the Australian Standardwind regions. All details for RHS/CHS posts such as stiffener/bolt connection, stiffenerspacings, connector straps and rivets are satisfactory for Region D.

(iii) Catering for Larger Signs

The Guide now caters for signs up to 7.5m wide, 8m high and 40m² in area.

There are now 3 tables for each wind region, refer to Appendix B, with one tablededicated to the smaller signs (<10m²) and one dedicated to larger signs (10 to 40m²),which includes truss supports.

Standard Drawings SD 1366 and SD 1367, Appendix D, detail the manufacturingrequirements for trusses.

(iv) Modular Sign Panels

Modular Sign panels have been included in the Guide. A sketch and details ofconstruction are shown in Section 5.

(v) Plank Board Signs

Plank boards are a smaller version of the modular system where the stiffener is built intothe extruded aluminium plank. Section 5 outlines the design and erection advantages ofthis system. Trial plank boards have been erected in Metropolitan South and NorthDistricts.

(vi) Breakaway Details

Breakaway support details have been standardised for CHS and RHS supports andare detailed on Standard Drawing SD 1365, Appendix D.

(vii) Single Support Slip Base

A slip base for single supports has been provided. Details are on Standard DrawingSD 1368, Appendix D.

2. New Appendix

A TraSiS Details.

Design Guide for Roadside Signs Preface

Issue: February 2001 vii

Version History:

First Issue Draft Edition A, Rev 0, June 1996 Design Guide for Road Signs.

Second Issue Draft Edition A, Rev 1, June 1996 Design Guide for Roadside Signs.

Third Issue Edition 1, Rev 0, Design Guide for Roadside Signs (2000).

Fourth Issue Edition 1, Rev 1, Design Guide for Roadside Signs (2001).

Preface Design Guide for Roadside Signs

viii Issue: February 2001

Table of Contents

SECTION 1. SCOPE AND INTRODUCTION ..................................................................11.1 SCOPE ..............................................................................................................................1

1.2 APPLICATION ...................................................................................................................1

1.3 OBJECTIVE .......................................................................................................................1

1.4 INTRODUCTION ...............................................................................................................1

1.5 REFERENCED DOCUMENTS ..........................................................................................1

1.6 DEFINITIONS ....................................................................................................................1

SECTION 2. DESIGN WIND PRESSURE .......................................................................32.1 GENERAL ..........................................................................................................................3

2.2 FAILURE MODE ................................................................................................................32.2.1 Steel supports .......................................................................................................32.2.2 Timber supports ....................................................................................................3

2.3 STRUCTURE IMPORTANCE MULTIPLIER .......................................................................3

2.4 DIRECTIONALITY ..............................................................................................................3

2.5 REGIONS ..........................................................................................................................3

2.6 TERRAIN CATEGORY .......................................................................................................4

2.7 GANTRIES AND CANTILEVERS .......................................................................................4

2.8 SPECIAL LOCATIONS ......................................................................................................4

2.9 SELECTION OF REGION AND EXPOSURE .....................................................................4

2.10 ADDITIONAL INFORMATION ............................................................................................4

SECTION 3. SIGN DESIGN ............................................................................................63.1 GENERAL ..........................................................................................................................6

3.2 SIGNS OF STANDARD DESIGN .......................................................................................6

3.3 SIGNS REQUIRING INDIVIDUAL DESIGN .......................................................................6

3.4 LETTERING .......................................................................................................................73.4.1 Selection of letter series .......................................................................................93.4.2 Calculation of letter height ..................................................................................12

SECTION 4. CLEAR ZONE CRITERIA .........................................................................154.1 GENERAL ........................................................................................................................15

4.2 FACTORS INFLUENCING THE CLEAR ZONE ...............................................................15

4.3 DETERMINATION OF CLEAR ZONE REQUIREMENTS .................................................15

4.4 OPPORTUNITIES TO REDUCE LATERAL CLEARANCES .............................................16

SECTION 5. SIGN FACE CONSTRUCTION .................................................................245.1 SIGN FACE MATERIALS ................................................................................................24

5.1.1 Sign substrate .....................................................................................................245.1.2 Sign sheeting ......................................................................................................255.1.3 Stiffener rails .......................................................................................................28

5.2 SIGN FACE CONSTRUCTION ........................................................................................305.2.1 Construction types ..............................................................................................30

Design Guide for Roadside Signs Table of Contents

Issue: February 2001 ix

5.2.2 Standard construction ........................................................................................305.2.3 Plank board construction ...................................................................................315.2.4 Modular construction ..........................................................................................335.2.5 Dovetail construction ..........................................................................................36

SECTION 6. SIGN ERECTION .....................................................................................386.1 GENERAL ........................................................................................................................38

6.2 SIGN LOCATION (DESIGN) ............................................................................................38

6.3 SIGN LOCATION (FIELD) ................................................................................................39

6.4 LOCATION OF SUPPORTS ............................................................................................406.4.1 Slip base orientation ...........................................................................................406.4.2 Support stub placement .....................................................................................40

6.5 EXCAVATION OF FOUNDATIONS ..................................................................................41

6.6 PREPARATION OF SUPPORTS ......................................................................................41

6.7 INSTALLATION OF SIGN SUPPORTS ............................................................................426.7.1 Foundations (poured concrete) ..........................................................................426.7.2 Erection of supports ...........................................................................................42

6.8 SUPPORT FINISHING .....................................................................................................43

6.9 ERECTION OF SIGN FACE ............................................................................................436.9.1 Small signs ..........................................................................................................436.9.2 Larger sized signs ...............................................................................................436.9.3 Flanges ...............................................................................................................436.9.4 Lifting of the sign face .........................................................................................436.9.5 Erection of a sign from the ground .....................................................................44

6.10 SIGN CHECK LIST ..........................................................................................................456.10.1 Sign design checklist ..........................................................................................456.10.2 Materials checklist ..............................................................................................456.10.3 Erection checklist ................................................................................................466.10.4 Sign erection check sheet (larger direction signs) ............................................47

6.11 EQUIPMENT CHECK LIST ..............................................................................................48

SECTION 7. SIGN FOUNDATIONS ..............................................................................497.1 CIRCULAR FOUNDATIONS ............................................................................................49

SECTION 8. SIGN SUPPORTS ....................................................................................508.1 POST SIZE AND SELECTION .........................................................................................50

8.2 SINGLE POST SIGNS .....................................................................................................508.2.1 Signs up to 950mm wide ....................................................................................508.2.2 Sign posts ...........................................................................................................518.2.3 Fittings ................................................................................................................518.2.4 Signs over 950mm wide .....................................................................................518.2.5 Posts in sleeves ..................................................................................................51

8.3 MULTIPLE SUPPORT SIGNS ..........................................................................................518.3.1 Panel stiffener rails ..............................................................................................528.3.2 Sign supports ......................................................................................................528.3.3 Aternative post section sizes ..............................................................................53

Table of Contents Design Guide for Roadside Signs

x Issue: February 2001

8.3.4 Breakaway supports ...........................................................................................53

8.4 FITTINGS .........................................................................................................................558.4.1 Connection straps ..............................................................................................558.4.2 Erection cleats ....................................................................................................55

SECTION 9. STORAGE AND HANDLING OF SIGNS ..................................................569.1 GENERAL ........................................................................................................................56

9.2 GENERAL STORAGE ......................................................................................................56

9.3 INDOOR STORAGE ........................................................................................................56

9.4 OUTDOOR STORAGE ....................................................................................................56

9.5 SIGN TRANSPORT .........................................................................................................56

9.6 SIGN ERECTION .............................................................................................................56

9.7 SIGN COVERING ............................................................................................................57

9.8 SIGN CLEANING .............................................................................................................57

APPENDICESA TraSiS .............................................................................................................................59

B DESIGN PROCEDURE FOR ROADSIDE SIGN SUPPORT ............................................61

C COMPARISON OF 2001 DESIGN GUIDE WITH 1991 DESIGN GUIDE .........................79

D STANDARD DRAWINGS .................................................................................................91

Design Guide for Roadside Signs Table of Contents

Issue: February 2001 xi


xii Issue: February 2001


DEPARTMENT OF MAIN ROADSQueensland


SECTION 1. SCOPE AND INTRODUCTION

1.1 SCOPE

This guide sets out guidelines for the design and erection of roadside signs.

This guide does not cover cantilevers and gantries that overhang the carriageway.

1.2 APPLICATION

This guide is applicable to all types of roads under normal operating conditions.

1.3 OBJECTIVE

The objective of this guide is to provide a set of uniform guidelines for the design and erection ofroadside signs throughout Queensland.

1.4 INTRODUCTION

The procedure for the design of signs in this guide should be applied from the initial design of thesign face through to the ordering of each sign component. The software program TraSiS guidesthe user through the design process. Appendix A provides details on the program together withinformation on how to purchase a copy.

1.5 REFERENCED DOCUMENTS

The following Australian Standards are referenced in this guide:

AS 1170.2-1989, SAA Loading Code, Part 2: Wind Loads

AS 1744 1975 - Standard Alphabets for Road Signs

1.6 DEFINITIONS

For the purpose of this guide, the following definitions apply:

AADT:

Annual Average Daily Traffic Flow (two-way) measured in vehicles per day (vpd) averaged overone year.

ADT:

Average Daily Traffic Flow (two-way) measured in vehicles per day (vpd).

Built-up area:

A road in a built-up area is defined as any road upon which there is a system of streetlighting.

Clear Zone:

The total roadside border area, starting at the edge of the travelled way, available for safe use byerrant vehicles and for the display of official traffic signs. This area may consist of a shoulder, arecoverable slope, a non-recoverable slope and/or a clear run-out area. The minimum clear zonewidth is dependent upon speed environment, AADT and roadside geometry.

Design Guide for Roadside Signs Scope and Introduction

Issue: February 2001 1

11

85th percentile speed (V85 km/h):

The speed at, or below, which 85 percent of vehicles are observed to travel under free-flowingconditions past a nominated point.

Pace:

A nominated speed range in which the greatest number of vehicles in traffic is observed to travelunder free-flowing conditions past a nominated point. For example, the 15 km/h Pace is the 15-km/h-speed range in which the largest percentage of vehicles is observed to travel.

Shall:

The word shall is to be understood as mandatory.

Should:

The word should is to be understood as non-mandatory, ie Advisory, or recommended.

Sign ground clearance:

The minimum distance in metres between the lower edge of a sign and the ground level directlybelow the lower edge of the sign.

Sign height:

The height in metres between the lower edge of a sign at the edge closest to the travelled wayand the level of the nearest edge of the travelled way, generally the edge line. The edge line isused as the reference point for determining the clear zone.

Speed limit:

The maximum speed at which a motor vehicle is legally permitted to travel on a particular sectionof road.

Scope and Introduction Design Guide for Roadside Signs

2 Issue: February 2001

11

SECTION 2. DESIGN WIND PRESSURE

2.1 GENERAL

It is proposed to use an appropriate probability of exceedence of the design wind speed toproduce results that are acceptable to both design life and a road safety. The following clausesoutline the structural assumptions made in this guide.

2.2 FAILURE MODE

2.2.1 Steel supports

To prevent the hazard of flying sign panels, it is important that signs should fail by pole bendingbefore failure of either stiffener rails or panel fixing. To ensure that signs are not blown off beforethe poles bend, stiffener rails are designed for the maximum design wind pressure, with anadditional safety factor of 1.67. This factor has been derived from the combination of load factorand capacity reduction factor on the pole (1.5 and 0.9 respectively).

The sign-face pressure is reduced when the steel pole bends in plastic bending.

2.2.2 Timber supports

Timber, by its very nature, is a non-plastic material and therefore cannot fail by plastic polebending. As the timber pole failure may lead to signs being blown across the carriageway,causing damage to property and people, different factors to the steel support must be used.

2.3 STRUCTURE IMPORTANCE MULTIPLIER

The structure importance multiplier, Mi in AS1170.2, represents a probability of exceedence of adesign wind speed. For Mi = 1.0 there is a 5% chance of exceedence of the Ultimate Wind Speedin a 50 year return period. For Mi = 0.9, as used in the 1991 Design Guide, the chance ofexceedence in 50 year and 1 year return periods is 25% and 0.5% respectively.

The proposed structure importance multiplier for steel supports, which relates to the maximumacceptable chance of exceedence, is Mi=0.75, ie the chance of exceedence in 50 year and 1 yearreturn periods is 96% and 6.5% respectively. That is, every year there is a 6.5% chance of the signexperiencing its design ultimate wind speed.

For timber, the desirable failure mode is different and an Mi of 1.0 has been adopted.

2.4 DIRECTIONALITY

It is improbable that the direction of the wind will always be in the critical direction for a signstructure. To allow for this fact, in non-cyclonic regions AS 1170.2 allows a wind speeddirectionality factor of 0.95 to reduce the value of design wind speed.

As the design wind for a particular locality generally blows from one direction, depending on theroad orientation, some signs will never experience the design wind speed in their critical direction.It is therefore proposed that the directionality factor is further reduced to 0.9 in non-cyclonicregions.

Viewing the performance of the road signs structures globally, rather than designing fordirectionality in each individual sign, justifies use of the reduced directionality factor of 0.9.

2.5 REGIONS

Signs in the different geographic regions defined in AS 1170.2 (A, B, C and D) are designed forthe wind speed related to that particular region.

Design Guide for Roadside Signs Design Wind Pressure


22

2.6 TERRAIN CATEGORY

Terrain Categories as such are not used. The Region classification relates to Terrain Category 3and 4. For exposed locations similar to Category 2 see Clause 2.8.

2.7 GANTRIES AND CANTILEVERS

The design philosophy outlined in Clauses 2.2, and 2.3 does not apply to sign gantries orcantilevers that extend over traffic lanes, which are excluded, from the Guide. These signs shouldbe designed in accordance with AS 1170.2, with a minimum design life of 50 years.

2.8 SPECIAL LOCATIONS

High-risk areas, likely to be exposed to high wind speeds regularly, should be identified and therisk assessed. This risk can be reduced by the use of the exposed category (Category 2 ofAS1170.2) or an increased section size. Typical locations that should be considered are:

� Houghton Highway (across water adjacent Moreton Bay)

� Gateway Bridge (high, exposed position)

� Some sections of Gateway Arterial adjacent to Brisbane Airport

� Gold Coast Highway at Kirra and other coastal positions.

2.9 SELECTION OF REGION AND EXPOSURE

For those locations not listed in Clause 2.8, the following procedure for the selection of theappropriate Design Table is recommended:

(1) Identify Region A, B, C or D, refer to Figure 2.1.

(2) Consider whether or not the region is particularly exposed or at risk. If so, increase Region Ato B, B to C, and C to D. The exposed category in Region D will require a step in sectionmodulus of the tabulated posts, or an additional post. (D Regions are normally only found inWestern Australia).

(3) Refer to Table 2.1 to determine the appropriate table, B.3.1 to B.3.12. B3 tables can be foundin Appendix B to this guide.

Situations outside the scope of these tables, or standard sections, should be checked anddesigned by a Structural Engineer. Extrapolation of these tables is neither appropriate noracceptable.

2.10 ADDITIONAL INFORMATION

The Traffic Engineering Section, Traffic Engineering & Road Safety Branch holds designcalculations, which outline the basis for the design charts and development of the truss system.

Based on various Australian Standards, assumptions have been made on the performance of thesign structure as a whole. Full scale structural testing is recommended to confirm theseassumptions.

Design Wind Pressure Design Guide for Roadside Signs


22

TABLE 2.1 APPLICATION TABLES FOR REGIONS

Region Sign Size Range Applicable Table

A � General 0 � 10m² B.3.1 (RHS/CHS)

8 � 28m² B.3.5 (RHS/CHS)

15 � 40m² B.3.9 (Trusses/RHS)

A � Exposed 0 � 10m² B.3.2 (RHS/CHS)

B � General 8 � 28m² B.3.6 (RHS/CHS)


B � Exposed 0 � 10m² B.3.3 (RHS/CHS)

C � General 8 � 28m² B.3.7 (RHS/CHS)


C � Exposed 0 � 10m² B.3.4 (RHS/CHS)

D � General 8 � 28m² B.3.8 (RHS/CHS)


D � Exposed 0 � 10m² B.3.4 (RHS/CHS) Increase one section size

8 � 28m² B.3.8 (RHS/CHS) Increase one section size


Increase one section size

FIGURE 2.1 GEOGRAPHIC REGION

Hobart

CanberraSydney

Brisbane

Melbourne

Adelaide

303

Region A

Region B

Region C

Region D

0

25

20

25

Perth

Green HeadGunyidi

Morawa

Mullewa

Gallathard

Gascoyne Junction

Mt Amy

Millstream

Marble Bar

Onslow

Croydon

Pt. Hedland

Broome

DerbyWyndam

Ivanhoe

Adelaide River

Katherine

Borroloola

Burketown

West Moreland

Weipa

McDonnel

Moreton

Dunbar

Atherton

Cooktown

Cairns

Mareeba

Townsville

Bowen

Mackay

Rockhampton

Bundaberg

Maryborough

CasinoToowoomba

Glen Innes

Goffs Harbour

Grafton

Corindi

Emerald

Biloela

Monto

Charters Towers

Alice Springs

Collinsville

Carnarvon

Geraldton

Darwin

Design Guide for Roadside Signs Design Wind Pressure


22

SECTION 3. SIGN DESIGN

3.1 GENERAL

Sign types are classified in the 1995 Edition of Manual of Uniform Traffic Control Devices(MUTCD), Clause 1.5. These include Regulatory, Warning, Guide, Freeway Guide, Temporary andHazard Markers.

3.2 SIGNS OF STANDARD DESIGN

Most road signs are of a fixed content/legend and are provided in a range of standard sizesdesignated A, B, C or D. General guidance in the selection of the appropriate size is provided inthe various parts of MUTCD which pertain to a number of traffic situations.

Unless otherwise specified in the MUTCD, the following principles should be observed in sign sizeselection:

(a) For regulatory, warning and traffic instructions, the smallest designated available size shouldnormally be used -

(i) only where the 85th percentile approach speed is less than 70km/h;

(ii) where prominence or conspicuity of the sign is not affected by competing visual stimuli;and

(iii) where lateral displacement of the sign from the driver's path is not excessive.

(b) Progressively larger signs in the above categories should be used -

(i) as approach speeds become higher;

(ii) where a greater need exists for sign prominence due to competing visual stimuli or theneed to emphasise the message;

(iii) where there is excessive lateral displacement of the sign.

(c) The largest available sizes should be used on freeways.

(d) Where one sign supplements another, the two signs should be the same width. With theexception of the Time of Operation module (R9-1), this means that the same size designationie. A, B, C etc., should be used for both signs. When the Time of Operation module (R9-1) isused with Bus, Transit, Truck or Bicycle Lane (R7-1) signs, the former should be one sizedesignation smaller than the lane sign, so that the widths are equal.

(e) The parking series signs are classified according to a narrow and wide (N and W) designationseries. Guidelines for the appropriate selection of parking series signs are provided in Clause4.4.2 - Part 11 of MUTCD.

For standard signs, the design and layout of the sign face will be in accordance with MUTCD andAS 1743 requirements. In most cases, these signs have a standard legend and layout. Theprovision of the MUTCD number, size details and sheeting class is generally sufficient for orderingpurposes.

3.3 SIGNS REQUIRING INDIVIDUAL DESIGN

These signs typically belong to the Guide Sign series and include service, tourist and historicalsigns. Guide signs inform and advise road users about the direction and distances of destinationson the route they are following, or along other roads which intersect their route. They also supplyinformation to identify points of geographical or historical interest and give directions to rest,camping or parking areas.

Sign Design Design Guide for Roadside Signs


33

Due to these factors, several of the signs in the Guide Sign series can have a significant variationin size dependent upon the nature of the information being conveyed ie sign content/legend. Thesigns are identified in MUTCD by way of examples of the standardised format.

These guidelines assume that the designer has predetermined the sign content/legend.

As an overview, the following aspects should be considered in determining the size of a sign:

� lettering, word length and layout;

� arrows and chevrons;

� route markers;

� borders, edge strips and corners;

� standard substrate sizes; and

� retroreflective sheeting roll widths

3.4 LETTERING

Sign lettering used in Queensland is based on AS 1744-Standard Alphabets for Road Signs.

Figure 3.1 shows A and F lettering and the difference between the three standard spacing ofletters, narrow, medium and wide.

There are seven capital letter series in AS 1744 and one lower case. These are A, B, C, D, E,Modified E and F. The letter series vary based on stroke width and each has a range of spacingsbetween letters (narrow, medium and wide). The stroke width is the thickness of the line used tomake up the letter.

Series A is the narrowest of the letter series and is limited in use.

Table 3.1 based on Part 8 of the Guide to Traffic Engineering Practice NAASRA 1988, Part 8 setsout general usage for each series. The MUTCD also sets out minium requirements for individualtypes of signs. Lower case letters are normally used for direction names or locations on guidesigns and for abbreviations such as m (metres), km (kilometres) and t (tonnes). All directionnames or locations have an initial Modified E capital letter followed by the lower case letters.

TABLE 3.1 ALPHABET SERIES USAGE

Alphabet Usage Legibility DistanceSeries (metres per mm of

Capital letter height)

A Only used for signs which do not haveto be read from a moving vehicle

B Only used for signs which do not haveto be read from a moving vehicle

C Only used when absolutely necessary 0.5

D Suitable for general needs 0.6

E Most desirable and pleasing 0.7

Modified E Reserved for Guide signs 0.75(and Lower Case)

F Not generally used but may be desirablein certain applications

Design Guide for Roadside Signs Sign Design


33

FIGURE 3.1 LETTER SERIES AND SPACING



33

The height of the lettering determines the legibility of the alphabet series. Legibility is based on thedistance at which a sign can be read, which in turn affects the time available for a driver to readthe information on that sign.

The communication function of the sign depends on the words used, the number of words, themessage to be communicated and the use of symbols (if any).

These factors, together with environmental factors such as competing visual effects, determinewhether or not if the sign will be effective. The following procedure is used to determine aminimum standard for letter height for a particular sign:

(1) Select the letter series appropriate to the sign type;

(2) Calculate the appropriate legend height; then

(3) Check that the legend series is appropriate and recalculate if necessary.

3.4.1 Selection of letter series

Letter series have a differing legibility distance; the higher the alphabet series, the greater thedistance at which the sign can be initially seen and then read (refer Table 3.1). Additional details ofthe basis for the figures in Table 3.1 are set out in the equations in Clause 3.4.2.

Tables 3.2 and 3.3 have been compiled from Part 2 of the MUTCD and set out miniumrequirements for letter series in guide signs. Tourist and service signs are covered in Part 6 of theMUTCD and have the following requirements:

(i) Service signs have a white symbol or legend where appropriate on a blue background.

(ii) Tourist signs have a white legend on brown background.

The lettering on both service and tourist signs shall have a minimum size of 120mm and shouldbe Series D or E. Generally lettering is provided as follows:

A size signs - 140 DM and B size signs - 200 DM.

Where the tourist sign is combined with a direction sign, upper and lower case legend is used.Letter sizes may be the same as those on the direction sign or, where necessary, slightly smaller.

TABLE 3.2 GUIDE SIGNS

Sign Type Environment Comment(minium legend size)

ADVANCE DIRECTION SIGNS

Single Panel G1-4 Two Lane rural and two lane one 160 Mod Eway urban

Multi Lane rural, wider than two 240 Mod Elanes one way urban andoverhead signs

Multi-paneled G1-1, G1-2 and G1-6 As Above As Above



33

TABLE 3.2 GUIDE SIGNS (cont�d)


Diagrammatic G1-3, G1-5 As Above As Above

LANE DESIGNATION SIGNS

Single Direction G9-7, G9-8 OverHead Signs: Directional D or E Capsor Driving Instructions

Multiple Direction/ lane G9-42, Calculate for 43 series each sign

INTERSECTION DIRECTION SIGNSSingle Chevron G2-1 160 Mod E

Double Chevron G2-4 160 Mod E

Square Ended G2-2, G2-5 As Above

Road Name Board G2-3 Lower caseheights of G2-1

FINGER BOARDS

G3-3 100 Mod E min140 Mod E max

Road Name Boards G3-4 C, D or E CapsLower caseheights of G3-3



33

TABLE 3.2 GUIDE SIGNS (cont�d)


Rural Road Name Signs G3-5 120 or 140 C,Dor E Caps

REASSURANCE DIRECTION G4-1 140 Mod E

TABLE 3.3 FREEWAY GUIDE SIGNS

Sign Type Environment Lettering (min) Instructional (min)

ADVANCE EXIT & EXIT DIRECTION GE1-5, 6, 7, 9, 10, 11, 400 Mod E 320 EM12, 13, 14, GE2-1,GE2-2

SUPPLEMENTARY ADVANCE SIGNS GE1-8 320 Mod E

REASSURANCE GE4-1 Urban 240 Mod E 180 D or CRural 180 Mod E 140 D or C

INTERCHANGE G1 series Advance Direction 180 Mod E 160 EMon Exit Ramps

INTERCHANGE G2 series Intersection Direction 180 Mod Eat exit ramp terminals

INTERCHANGE Advance Direction Major Urban 240 Mod E 200 DMon cross street for entrance ramps Minor Urban and 180 Mod E 160 DMG1 series Rural

INTERCHANGE Intersection Direction Major Urban 240 Mod Eat entrance ramps G2 series Minor Urban 180 Mod E

and Rural



33

3.4.2 Calculation of letter height

The following extract from Appendix D of Part 2 of the MUTCD sets out a method for determiningthe size of letters to be used on signs requiring individual design. The derivation of theseequations is given in AUSTROADS, Guide to Traffic Engineering Practice, Part 8: Traffic ControlDevices.

Determine the capital letter sizes using the following equation:

H = 0.14NV + 11.4S Equation 1

where:

H = capital letter height in millimetres, including height of initial capitals used with lower caseletters;

N = number of words on the sign;

V = approach speed in kilometres per hour;

S = lateral offset of the sign in metres, measured from the centre of the sign to the centre ofthe traffic lane.

The equation applies to words made up of Series E Modified capitals and lower case letters, egon direction signs, on side-mounted signs in rural areas. For other conditions the equation shouldbe modified as follows:

(a) For other letter series increase H by the following factors:

Series C = 50%, Series D = 25%, Series E = 7%.

(b) For signs in urban areas increase H by 25% (conspicuity adjustment for urban environments).

(c) For overhead signs, S used in equation should be vertical offset of sign centre from driverseye height multiplied by 2.

(d) Where an overhead sign is at the side of the road and more than 3 m from the edge of thepavement, it may be necessary to calculate the equivalent lateral distance SEL from theformula:

SEL = (SL2 + 4SV

2)1/2 Equation 2

where:

SL = lateral offset of the sign in metres, as for Equation 1

SV = vertical distance of the centre of the sign above the drivers eye in metres, (distanceabove road surface, minus 1.2m)

The value SEL is then substituted for S in Equation 1.

To facilitate sign design and manufacture it will usually be necessary to adopt a standard lettersize given in AS 1744, nearest to the size calculated. These are as follows: 40, 60, 80, 100, 120,140, 160, 180, 200, 240, 280, 320, 340, 400, 480, 560, and 640.

All signs should be checked as part of the design process to ensure that the letter size isappropriate.

Figure 3.2 shows an example for the calculation of the basic minimum distances that should beinput to the above equations.

The following results were obtained using the measurements in Figure 3.2 and assuming thefollowing values:

(1) Width of lanes = 3.5 metres



33

(2) Number of Words = 5

(3) Speed V = 100 km/hr

(4) Each additional lane 3.5 metres

TABLE 3.4 CALCULATED LETTER HEIGHTS IN MILLIMETRES

Road Description Sign 1 Sign 2 Sign 3(Side of Road) (Overhead on side of Road) (Overhead far lane)

Two Lane, Two Way 184 (200) 216 (240) 184 (200)

Four Lane, Two Way 224 (240) 243 (260) 191 (200)

Six Lane, Two Way 263 (280) 276 (280) 209 (240)

Eight Lane, Two Way 304 (320) 310 (320) 235 (240)



33

FIGURE 3.2 CALCULATION OF OFFSET DISTANCES

2 Lane Two Way Road

4 Lane Two Way Road

Sign 1

Sign 2

Sign 3

S = 10

= 8, S = 5; S = S = 12.8

S = 10

S

Sign 1

Sign 2

Sign 3

S = 13.5

= 11.5, = 5; = S = 15.2

= 3.5, = 5; = S = 10.6

S S S

S S S

13.5 m

11.5 m

1.2 m

5 m3.5 m

1

2 3CL

CL

CL

10 m

8 m

1.2 m

5 m

1

2 3

CL

CL

CL

L V EL

L V EL

L V EL



33

SECTION 4. CLEAR ZONE CRITERIA

4.1 GENERAL

This section defines the extent of the clear zone relative to the edge of the travelled way. Signsupports in the clear zone should be frangible or break away.

The clear zone concept adopted by the Department is an accepted means of diminishing the riskof errant vehicle collision with roadside objects and maintaining the effectiveness of official trafficsigns.

Whilst the concept draws on a wide range of experience and research, engineering judgementshould be applied when determining the requirements for lateral position. These guidelinesshould be regarded as a supplement to aid in exercising this judgement, rather than a substitutefor it.

4.2 FACTORS INFLUENCING THE CLEAR ZONE

Variables that influence the determination of the clear zone for roadside signs include thefollowing:

� speed environment;

� roadside cut/fill slopes;

� road curvature;

� traffic volume (AADT); and

� presence of physical devices that limit or prevent errant vehicle incursion (eg. barrier rail orsteep cutting).

Once these variables are established, a simple procedure enables the clear zone to bedetermined.

4.3 DETERMINATION OF CLEAR ZONE REQUIREMENTS

The influence of the variables in Clause 4.2 on the width of the clear zone is determined byassessing the device site in accordance with the following:

� The clear zone is measured by extending a horizontal plane from the edge of the travelled wayto the edge of the device, as indicated in Figure 4.1.

� Figure 4.2 is used to establish the required clear zone distance for signs located on straightroads, given a designated speed environment, the slope of the roadside and traffic volume(AADT).

� A combination of Figures 4.2 and 4.3 is used when the sign is located on a curve in the roadalignment. The horizontal curve multiplier established from Figure 4.2 recognises the higherrisk and greater encroachment distance for errant vehicles on curved road alignments.

� A combination of Figures 4.2 and 4.4 is used to assess the influence of cut height and slope ontraversability when the device is located on a cut slope.

� Figures 4.5 and 4.6 provide examples of the influence of cut height and slope on traversabilityand opportunities to reduce lateral clearance.

� Figure 4.7 provides an example of clear zone calculations on variable slopes. On such slopes,it is necessary to approximate the contributory influence of each slope element, noting thatnon-recoverable fill slopes (ie. slopes steeper than 4:1) are disregarded in the calculation.

Design Guide for Roadside Signs Clear Zone Criteria


44

4.4 OPPORTUNITIES TO REDUCE LATERAL CLEARANCES

The requirements outlined in this section also present a number of avenues by which the �base�clear zone distance may be reduced (ie. the base clear distance determined for a device locatedadjacent a straight road). Given the significant advantages in placing a sign as close as possibleto the observer's line of sight, it is expected that the following avenues will be actively pursued:

(i) Device located on a suitable cut slope:

The clear zone distances determined from Figure 4.2 (for speed environments exceeding 60km/h) converge to a minimum permissible distance of 4.5m for traversable cut slopes steeperthan 2:1. As is apparent from Figure 4.2, advantages accrue when cut slopes steeper than6:1 are encountered, in that signs may be located closer to the travelled way.

See diagrammatic example, Figure 4.6 - Case (i).

(ii) Devices with a lateral offset of the device face from the supporting structure and groundclearance exceeding 5.4m:

Where the device face has a ground clearance closest to the travelled way exceeding 5.4m,the lateral offset is measured to the closest support rather than the device face.

See diagrammatic example, Figure 4.6 - Case (ii).

(iii) Devices located behind non-traversable cut slope or barrier:

A non-traversable cut slope or barrier (eg guard rail) also potentially enables the sign to belocated within the calculated base clear zone.

Figure 4.4 provides a means by which cut slope traversability can be established. As withCase (ii), this relaxation limits the minimum clear separation between the travelled way andthe edge of the device face to 4.5m.

It is not permissible to install a barrier on steep fill slopes for the sole purpose of enabling therelaxation outlined in (iii), except where the barrier results in a lower hazard potential thanexisted before its installation. Applications that propose the installation of a traffic barrierrequire an engineering risk assessment, in accordance with recognised best practice.

See diagrammatic examples, Figures 4.5 and 4.6 - Case (iii).

Clear Zone Criteria Design Guide for Roadside Signs


44

FIGURE 4.1 CLEAR ZONE BASE PARAMETERS



44

FIGURE 4.2 CLEAR ZONE DISTANCE CURVES FOR STRAIGHT ROADS

NOTES:

Clear zone curves adapted from AASHTO "Roadside Design Guide"

This diagram does not identify all situations. For curved roads and roads on cut slopes, the clear zone is determinedby using the above diagram in conjunction with Figure 4.3 (Curve Adjustment Factors) and Figure 4.4 (Influence of CutHeight and Slope on Traversability). For roads on variable slopes, the diagram is used in conjunction with theexplanation given in Figure 4.7.

Example 1

1:6 Fill Slope

100 km/h Speed Environment

5000 V.P.D.

Clear Zone = 9 m

Example 2

1:6 Cut Slope


750 V.P.D.

Clear Zone = 6 m

Clear Zone Distance (m)

1:3

0 6 9 15 24 27

1:4

1:5

FLAT

1:5

1:4

1:3

1:6

1:6

1:10

1:10

1:8

1:8

1:20

1:20 FILL SLOPES

CUT SLOPES

��

��

��

��

�

��

��

��

Travelled way

ObstacleSlope

Travelled way

Slope

Obstacle

3 12 18 21 30OVER 6000 DESIGN A.D.T.

0 6 9 15 24 273 12 18 211500-6000 DESIGN A.D.T.

0 6 12 18 213 9 15750-1500 DESIGN A.D.T.

0 6 153 9 12UNDER 750 DESIGN A.D.T.

SLO

PE

SS

LO

PE

S

��

��

��

��

��

Exam

ple

1

Exam

ple

2

��



44

FIGURE 4.3 CLEAR ZONE HORIZONTAL CURVE ADJUSTMENT FACTORS

NOTES:

Horizontal curve adjustment factors adopted from AASHTO "Roadside Design Guide" are applied to the outside ofcurves only. Curves with a radius greater than 900m do not require an adjustment factor

Irrespective of the proposed device being located on a horizontal curve outside of the clear zone, consideration shallalso be given to any site accident history before approval is given for the erection of a device on a horizontal curve.

Curve Radius (m)

0

1

1.1

1.2

1.3

1.4

1.5

1.6

100 200 300 400 500 600 700 800 900

Ho

rizo

nta

lC

urv

eA

dju

stm

en

tF

acto

r

Exam

ple

3

60 km/h

70 km/h

80 km/h

90km

/h

100 km/h

110 km/h

Curve Radius

Example 3

450m Radius Curve


AADT > 6000 vehicles

CZ required on flat straight road = 9m (Figure 4.2)

Curve Adjustment Factor (Figure 4.3) = 1.40

Required Clear Zone = 9 x 1.40 = 12.6m



44

FIGURE 4.4 INFLUENCE OF CUT HEIGHT AND SLOPE ON TRAVERSABILITY



44

FIGURE 4.5 EXAMPLES, INFLUENCE OF CUT HEIGHT AND SLOPE ON TRAVERSABILITY



44

FIGURE 4.6 EXAMPLES OF OPPORTUNITY TO REDUCE LATERAL CLEARANCE



44

FIGURE 4.7 EXAMPLES OF CLEAR ZONE CALCULATIONS ON VARIABLE SLOPES



44

SECTION 5. SIGN FACE CONSTRUCTION

5.1 SIGN FACE MATERIALS

A sign face as supplied by a manufacturer to the Department of Main Roads specificationES126-1999 will comprise the following:

� sign substrate;

� sign sheeting;

� stiffener rails (if required).

The sign face panel is the completed unit with stiffener rails attached.

FIGURE 5.1 SIGN FACE ELEMENTS

5.1.1 Sign substrate

Signs are manufactured using stiffened or unstiffened plates depending on the size of the signand the restraints in Section 4. Two types of plate are used:

1. Aluminium

2. Zinc/Aluminium Coated Steel

Generally, the following selection guidelines should be adopted:

Sign Face Construction Design Guide for Roadside Signs


55

(1) All signs, except temporary signs and parking signs, should be manufactured from 1.6mmaluminium;

(2) All temporary signs shall be manufactured from 1.0mm zinc/aluminium coated steel; and

(3) Parking signs can be manufactured from either 1.6mm aluminium or 1.2mm zinc/aluminiumcoated steel. The choice is at the discretion of the designer.

Aluminium, 1.6mm thick, is the preferred sign substrate material due to cost, material quality, thepreference of retro-reflective sheeting manufacturers and national uniformity. It should also benoted that 1.2mm zinc/aluminium-coated steel is more than twice the weight of 1.6mm aluminium.

5.1.2 Sign sheeting

The following sheeting materials are available:

� Class 1A

� Class 1

� Class 1W

� Class 2A

� Class 2

� CAL (Non-reflective)

The first five refer to retro-reflective materials with Class 1A having the highest luminous intensityand Class 2, the lowest.

Class 1A Material

This material has the highest luminous intensities of all the sheetings. Its use is generally restrictedto symbolic signs or signs that have a greater separation to the incident light source (e.g.overhead signs). Special consideration needs to be given to the halation effect (brightbackground overwhelms the legend and/or the opposite).

Class 1 Material

Class 1 material has the longest guaranteed life (12 years). It is recommended for use in thefollowing circumstances:

(1) Urban locations where ambient light and surrounding environment demand the use ofhighest intensity signs (e.g. with a high level of street lighting).

(2) Overhead position or at such lateral distance from the carriageway that only a smallproportion of the headlight falls on the sign.

Class 1W (Wide Angle) Material

This material has lower luminous intensity than Class 1A but higher than Class 1. The sheeting isdesigned to return light from a drivers vehicles headlights back to motorists eyes at wideobservation angles. It is recommended for use in the following circumstances:

(1) Urban localities with a number of competing visual stimuli and short viewing distances.

(2) Disadvantaged sign locations.

This class of sheeting will be required to undergo the durability testing required of Class 1Amaterial for approval purposes. The minimum coefficients of luminous intensity per unit area forthis sheeting are:

Design Guide for Roadside Signs Sign Face Construction


55

RTA - NSW specification for a designated enhanced Class 1 sheeting (Class 1W)

Class 2A Material

This class has luminous properties intermediate between Class 1 and Class 2 and has aguaranteed life of 8 years. However, for some colours such as green and red, the luminousintensities of this class of material are very similar to those of Class 1 but at a lower cost(approximately 15% lower) and have a guaranteed life of 10 years.. It is much more robust, (i.e.will take more physical abuse/handling), than Class 1 material.

Class 2A sheetings are recommended for use in the following circumstances:

Situations where Class 1 sheetings are not required and where better than Class 2 performance isrequired.

As an alternative to Class 1 on Regulatory and Warning Signs and Hazard Markers intended forlocations where the life expectancy of 8 years is adequate.

Class 2 Material

This class of sheeting has the lowest luminous intensity and guaranteed life (7 years) of the threeclasses of retro-reflective sheetings available. It is as robust as Class 2A material. It should beused in the following situations:

(1) Rural environments generally except for overhead positions and lateral positions where only asmall proportion of headlight falls on the sign.

(2) Urban environments where there is little or no ambient light.

CAL

CAL is a non-reflective material which has previously been used as a background material onDirection Signs (Standard Green), Temporary Signs, Parking Signs and Information Signs. Use isnow limited to signs that do not need to be seen at night or for black lettering.

The sheeting materials recommended for use with various sign types are listed in Table 5.1. Thematerials shown for Direction, Tourist and Service and Freeway signs are for the legend andbackground respectively.

Entrance Observation Minimum CIL/m² valuesangle αα angle ββ (cd/lx.m²)

(degrees) (degrees) White Yellow Red Standard BlueGreen

4 0.2 430 340 80 45 200.33 300 210 50 30 151.0 40 24 8 4 2

15 0.2 370 300 68 40 170.33 250 190 42 25 111.0 30 19 5 4 1

30 0.2 235 190 50 30 110.33 150 130 30 16 71.0 18 16 4 2 1



55

Notes:

¹ Class 1A may be adopted in circumstances of high ambient light or visual clutter or at particularlyhazardous locations (B and C sized signs only).

² Class 1 �construction work zone material� has high durability and retroreflective performance and maybe considered for roadworks signing applications.

³ Class 1A or 1W may be adopted in circumstances of high ambient light or visual clutter (urban), or toidentify particularly hazardous locations.

TABLE 5.1 RECOMMENDATIONS FOR SHEETING MATERIAL

Sign Type and Application Recommended(where applicable) Minimum Class of Sign Material

Legend Background

Regulatory Signs:STOP (R1-1)¹ Class 1W screenedGIVE WAY (R1-2)¹ screened Class 1WRoundabout (R1-3)¹ screened Class 1WPedestrian Crossing (R3-1)¹ N/A Class 1WSafety Zone (R3-2) N/A Class 1

Warning Signs:Stop Sign Ahead (W3-1) Class 2A Class 2ARoundabout Ahead (W3-2) Class 2A Class 2ARAILWAY CROSSING Position (W7-1) N/A Class 1(Number)�TRACKS (W7-2) N/A Class 1

Guide Signs:NOTE: A minimum of Class 2 Background applies to both Urban and Rural applications.It is suggested that the following combinations should generally be applied. However exceptionalcases will exist.

Advance, Intersection, Reassurance Direction signsand Advance Lane signs:Rural Class 1 Class 2Urban Class 1 Class 1Tourist and Service Signs:Rural Class 1 Class 2Urban Class 1 Class 1Geographical Feature and Street Name Signs:Rural N/A Class 2Urban N/A Class 1Freeway Signs (White on Standard Green background;Black on White background; White on Blue background;Black on Yellow background; White on Red background):

All applications: Class 1 Class 1Traffic Instruction Signs:REDUCE SPEED (G9-9) Class 1 Class 1

Roadworks and Special Purpose Signs² N/A Class 2

Hazard Markers³ N/A Class 1Delineators Class 1A or Corner Cube (Type A)



55

5.1.3 Stiffener rails

Stiffener rails are normally manufactured from an extruded aluminium section, alloy type 6061 or6063, temper T6 to the dimensions shown on Standard Drawing 1369. Figure 5.3 shows StandardDrawing 1369. Figure 5.2 shows a range of rail stiffeners including dovetail and plank board sectionsthat perform the basic function of allowing the plate to be attached the support usually by the use ofsaddle fittings or brackets. Saddle fittings and brackets are discussed in greater detail in Section 5.2.

FIGURE 5.2 STIFFENER RAIL AND PLANK CROSS-SECTION

Attachment of the stiffener rail to the plate can be achieved in various ways. These include:

(a) 4.8 to 5mm diameter monel or stainless steel pop rivets;

(b) 4.0mm diameter blind aluminium head pop rivets; or

(c) self-piercing riveting systems.

No. 10 gauge, cadmium-plated self-drilling screws have been removed from ES126 due to rustingproblems and the visual appearance of the screw heads. The heads of rivets or other similarfixings should be coloured to match the surrounding material.

The maximum spacing of mechanical fixings is 200mm and the distance from the first fixing to theedge of the stiffener is not greater than 30mm. For other proprietary fixing systems, themanufacturer of the fixing system should define minimum requirements. An additional fixing isinstalled 20mm from the first fixing.

Type 2AType 1 Type 2A Modified

“Signfix” Large Mate®

“Signfix” Dovetail®

Typical Plank Board



55

FIGURE 5.3 STANDARD DRAWING 1369 - SIGN STIFFENING EXTRUSIONS

TR

AFFIC

SIG

N

Dra

win

gN

o

1369

Dat

e03

/200

1

Siz

eA

4

A

Not to

scal

e

Type

1 2A

2A

(mod

.)

15375

88950

90234

27232

104520

115585

242

487

504

Are

am

m²

Ixx

Iyy

DET

AIL

SO

F

SIG

NS

TIFF

ENIN

GEX

TRU

SIO

N

Note

s:

1.M

ater

ial:

Stru

ctur

al g

rade

606

1-T6

or

6063

-T6.

2.Ty

pe 2

A is

equ

ival

ent i

n sh

ape

to “

SIG

NFI

X”Ty

pe 2

stif

fene

r N

o. Q

355A

.

3.Fi

nish

: A

rchi

tect

ural

.

4.To

lera

nces

: In

acc

orda

nce

with

Aus

tral

ian

Stan

dard

186

6-19

86.

5.N

o co

pyrig

ht o

n th

e Ty

pe 1

, 2A

or

mod

ified

Type

2A

sec

tions

is h

eld

or w

ill b

eac

know

ledg

ed a

s be

ing

held

by

any

com

pany

whi

le th

ese

sect

ions

are

spe

cifie

das

bei

ng s

uita

ble

for

use

as s

ign

stiff

ener

s.

6.Fi

xing

Sig

n Pl

ates

to S

tiffe

ner

Rails

Fixi

ng o

f sig

n pl

ates

to s

tiffe

ner

rails

sha

ll be

by

eith

er:

(a)

4.8

to 5

mm

dia

met

er m

onel

or

stai

nles

s st

eel r

ivet

s;

(b)

4.0m

m b

lind

alum

iniu

m h

ead

rivet

s;

(c)

self

pier

cing

riv

ettin

g sy

stem

s; o

r

(d)

any

fast

enin

g sy

stem

that

has

an

equi

vale

nt p

erfo

rman

ce c

hara

cter

istic

as

(a),

(b)

or (c

) abo

ve.

Cad

miu

m p

late

d se

lf dr

illin

g sc

rew

s or

oth

er ty

pes

of s

crew

s sh

all n

ot b

e us

ed. T

hehe

ads

of r

ivet

s or

oth

er s

imila

r fix

ings

sha

ll be

col

oure

d to

mat

ch th

e su

rrou

ndin

gm

ater

ial.

Offe

rors

sha

ll st

ate

the

type

(s) o

f fix

ings

pro

pose

d to

be

used

.

The

max

imum

spa

cing

of m

echa

nica

l fix

ings

sha

ll be

200

mm

and

the

dist

ance

from

the

first

fixi

ng to

the

edge

of t

he s

tiffe

ner

shal

l be

not g

reat

er th

an 3

0mm

or

assp

ecifi

ed b

y th

e su

pplie

rs o

f the

fixi

ng s

yste

m. A

n ad

ditio

nal f

ixin

g 20

mm

from

the

first

fixi

ng s

hall

be a

pplie

d. A

n ex

cept

ion

to th

is is

the

use

of th

e “H

enro

b” s

elf

pier

cing

riv

etin

g sy

stem

, for

whi

ch th

e m

axim

um fi

xing

spa

cing

sha

ll be

250

mm

.

28.5

R3.5

Full

R25.5

3.25

3.2

2.5

5.7

1.5

11

TYPE

1

44

40

3.5

3.15

2.5

3

8

77

3

1123

3

R

RR

R =

2.0

Rad

.T

= 0

.5 R

ad.

TYPE

2A

45°

TT T

T

TT

TT

TV

VT

R

29

MO

DIF

IED

TYPE

2A

44

40

3.8

3.15

2.8

3.2

8

77

3.8

1123

3

Z

ZZ

R =

0.5

Rad

.T

= 1

.0 R

ad.

Z =

2.0

Rad

.

45°

RR T

T

TT

TT

RV

VR

Z

29 11.6

TT

14

11.2



55

5.2 SIGN FACE CONSTRUCTION

5.2.1 Construction types

Section 8 describes how to determine the number and placement of stiffeners required for thesignface.

For larger signs, using the maximum stiffener spacing can lead to problems when attempting toerect a large sign in one piece. Several alternate signface designs have been devised toovercome this problem. Such alternative construction methods shown in Figure 5.4, include:

1. Standard

2. Plank Board

3. Modular

4. Dovetail

FIGURE 5.4 STANDARD, PLANK BOARD, MODULAR AND DOVETAIL CONSTRUCTION

5.2.2 Standard construction

The standard way of supplying a sign in sections is shown in Figure 5.5.

The stiffener rail is used to span the horizontal joint and the sections are usually predrilled thenriveted on site. The depth of panels varies depending on the stiffener spacing and cut plate sizes.



55

FIGURE 5.5 STANDARD CONSTRUCTION (STIFFENER ON SIGN EDGE)

A system which uses panel modules of 1.2m is the recommended method for large signconstruction, when the sign cannot be transported in a single piece. An alternative approach is touse specialist stiffeners such as the Signfix Dovetail system.

5.2.3 Plank board construction

Plank boards signs comprise interlocking planks extruded from high tensile aluminium in depthsof 200 and 300mm. Figure 5.6 shows a typical plank sign detail, with another plank about to beattached.

To construct a sign using planks, each individual plank is layered on top of another and held inplace using plank clips. The centre channel is then attached to the sign supports by a saddlebracket.

Where staggered joints are allowed to be used channel couplings are required to be used acrosseach joint. Figure 5.7 shows a typical channel coupling and plank clip.



55

Plank boards are recommended for larger signs, gantries, cantilevers and sites where transport orerection could be difficult. For small signs erection is possible using ladders rather than cranes.

The use of planks for street name, stream name and other signs 200 and 300mm deep is alsorecommended due to the planks stiffeners and the need for less saddle fittings.

FIGURE 5.6 PLANK BOARD CONSTRUCTION

Advantages

� Readily available;

� Sign surface is rivet free;

� Easy to transport, move and handle than plate signs;

� Can be installed using ladders;

� Can be stored on edge without damaging the retro-reflective film;



55

� Increments of 100mm can be achieved when calculating sign size of 300 and 200 planksavailable;

� Individual planks can be replaced rather than the whole sign;

� Fast erection times are achievable;

� Appearance can be improved as no rivets or buckling;

� Planks can be re-sheeted and re-used easier than plates.

Disadvantages

� Higher material costs due to a thicker cross section;

� Higher wastage due to more off-cuts;

� Design of the sign face should allow positioning of legends away from plank edges;

� Rounded sign corners are not obtainable without hand jigsaw cutting;

� Difficult to cut lengths, as a cutting saw rather than a guillotine is required;

� Plank clips and additional saddle fittings are required compared to a plate sign;

� More potential for dirt ingress and weathering on the cut edges of the Class 1 film signs;

� Screen-printing is difficult across planks.

FIGURE 5.7 PLANK BOARD CONSTRUCTION

5.2.4 Modular construction

Modular sign panels may be used for larger signs to reduce the difficulty of handling and erectingdifferent size sections or a single large sign.

Figure 5.8 shows a general arrangement for the assembly of modular panels. Each panel is 1.2metres high constructed as a normal panel sign except for the stiffener spacing and location.



55

FIGURE 5.8 MODULAR CONSTRUCTION

The modular system requires the stacking of panels on top of each other. The stiffeners arelocated to allow positioning on top of each other while the sign face sheeting overlaps to presentan appearance of a smooth sign face.

Saddle fittings are used to clamp the sign face to the supports avoiding the need for on siteriveting.

Figure 5.9 shows a detailed sketch of a modular sign using aluminium plate and type 2Astiffeners.

The location of the upper and lower stiffeners is not critical, provided panel overhang between thestiffener and the top or bottom of the sign does not exceed 150mm.

Detail A and B on Figure 5.9 shows the location and attachment of a typical Type 2A stiffener.

For the top of the modular panel and bottom of the next panel, the stiffener rails are arranged asshown in Detail C. Firstly, the lowest panel is attached by saddle fittings to the supports. Thebottom stiffener of the second panel is then rested on top of the stiffener of the first panel, beforebeing attached by its own saddle fitting to the support. This is repeated until the sign iscompleted, or a smaller panel is attached at the very top as per Detail D.



55

FIGURE 5.9 MODULAR SIGN PANEL DETAILS



55

For signs where the 580mm spread of stiffener rails could affect the visual appearance, due tominor deformation between stiffeners, 2mm thick sheeting or additional stiffener rails should beconsidered.

The use of the modular system is recommended for all large signs (deeper than 1.2 metres) thathave to be assembled on site.

The following is a summary of advantages and disadvantages of the use of a modular system.

Advantages

� No riveting required on site;

� Appropriate size for transporting;

� Reasonable size of section for lifting by crane;

� Reduces the stress on cover strips and rivets during erection;

� Appropriate size for storage;

� Transportable face to face to protect retroreflective sheeting face;

� Easier removal by sections and re-erection if required; and

� Formalises existing practice of transporting large signs in sections to assemble on site.

Disadvantages

� Additional stiffeners required;

� No advantage for regions close to the sign manufacturer, where large cranes are readilyavailable and the whole sign is transportable.

5.2.5 Dovetail construction

Dovetail construction is a variation of the standard construction (stiffener on sign edge) thatutilises a two-part interlocking channel section (dovetail) rather than two complete abuttingchannel sections.

Figure 5.11 illustrates the two-section dovetail construction.

The advantages of this system are

1. Improved rigidity and resistance to deflection;

2. Savings on the cost of channels; and

3. Savings on the number of fixing clips, as illustrated on Figure 5.12, which shows how a singleclip in the dovetail system replaces two in the conventional system.



55

FIGURE 5.10 DOVETAIL CONSTRUCTION FIGURE 5.11 DOVETAIL CHANNEL SECTIONS

FIGURE 5.12 DOVETAIL POST FIXING



55

conventional dovetail

SECTION 6. SIGN ERECTION

6.1 GENERAL

The method of sign erection is determined by the size of the supports, type, foundations, numberto be erected and other factors. The following section outlines some of the basic procedures andtechniques required to avoid potential problems.

Each sign erection team will have individual variations on these techniques. The supervisor shouldensure that the team procedures are appropriate for the job.

6.2 SIGN LOCATION (DESIGN)

For design purposes, the following information and assumptions are required.

1) A ground clearance to the sign, based on the sign environment

Items to consider include the following:� pedestrians;� possibility of vandalism;� type of ground cover;� steepness of terrain;� minimum clearance for breakaway supports; and� maximum clearance for truss supports.

For direction signs (rural and urban) allow adequate clearance for terrain changes,pedestrians, vandals and minimum clearance for breakaway supports. Further details can befound in the MUTCD Part 1.

2) Offset of the sign from the edge of the carriageway

This is normally 600mm. However, in high-speed environments, on roads with a highpercentage of large vehicles, this should be increased to a minimum of 1.0 metre. Location ofindividual supports then needs to be considered to avoid the following:� footpaths;� table drains;� excessive slope differences; and� known services.

3) Location of individual supports

Support spacing is a function of the sign width. Although spacing can be adjusted for specialcircumstances, it is preferable to use standard spacing to reduce the possibility of lostinformation or insufficient instructions reaching the erection team. Changes to the standardspacing, away from those in Table 6.1, should be highlighted and included in any installationinformation supplied.

TABLE 6.1 SUPPORT SPACING

Number % of sign widthof Supports Overhang Spacing Spacing Spacing Overhang

1 50 � � � 50

2 20 60 � � 20

3 15 35 35 � 15

4 12.5 25 25 25 12.5

Sign Erection Design Guide for Roadside Signs


66

Increased or decreased spacing affects the sign panel stiffness type and can lead tooverstressing. Consider increasing or decreasing the number of supports as the first designoption.

Offset signs have the same problems as those with non-standard spacing and need to beespecially designed. In some cases, additional stiffeners may be required which may causedifficulties for an existing sign panel.

4) Clear Zone

Reference to Section 4 is required to assist in the selection of the appropriate types ofsupports - rigid, frangible or breakaway.

5) Support Lengths

Once the location is determined, the support lengths can be estimated or specifieddepending upon the standard of information available.

In all cases, the critical support length used for the selection of support size is the largest.

The calculated support length should only be considered as a design length, to be confirmedon site.

6) Information to be supplied from the Design Team

The design team should supply the following information to the erection team:

(a) sufficient information to locate the sign relative to the road or carriageway. Normally thiscomprises a site plan and chainage;

(b) offset from a reference point to locate the leading edge of the sign and its orientation;

(c) sign depth and size (mm);

(d) sheeting class;

(e) number, type, design length (mm) and spacing of supports;

(f) number and size of fittings;

(g) type of stiffeners;

(h) design assumptions on terrain;

(i) foundation material, depth and diameter of hole;

(j) ground clearance;

(k) other critical factors such as to straddle footpath or avoid table drain; and

(l) reference to applicable standard drawings.

6.3 SIGN LOCATION (FIELD)

Using the supplied design information and standard installation details the following steps aresuggested:

1) Locate sign from site plan and chainage.

2) Mark the sign location on the road edge or by stake.

3) Locate supports, based on the design and site requirements. To eliminate possible vehicleheadlight reflection from the surface of the sign, the sign should be turned about 5 degreesaway from the normal to the headlight beam.

4) Check support lengths requirements against design lengths.

Design Guide for Roadside Signs Sign Erection


66

5) Refer to sign designer if site conditions change, or design assumptions are inappropriate e.g.ensure that the erection of the new sign does not adversely impact on existing signs.

6) Order supports, based on site length requirements.

In some cases, stubs may be ordered before support details are known, to allow for the fieldinstallation of stubs in readiness for the sign. This approach is recommended where terraininformation is limited or unknown.

The disadvantage of adopting this method is that a maximum slope must be assumed, andallowed for, when determining the section size. In the event that the site conditions are outside thisassumption, then the stub cannot be used for that particular site. The advantage of this method isthat the stub may be used for other sites, whereas a manufactured support cannot generally beused elsewhere.

6.4 LOCATION OF SUPPORTS

6.4.1 Slip base orientation

Slip base type mechanisms activate when two parallel plates slide apart as bolts are pushed outunder impact. The designs may be either uni-directional or multi directional. Slip bases for largersupports incorporating an upper hinge will be uni-direction. These slip bases need to be orientedtowards the likely approach path of an errant vehicle.

Slip bases for small sign supports (sign face < 5m²) can be either uni-directional (typically a 4 boltrectangular slip base) or multi-directional (typically a three bolt triangular or circular plate). Multidirectional slip bases are useful in road medians where the support may be struck from severaldifferent directions.

6.4.2 Support stub placement

Issues to consider:

� compaction and curing of the concrete;

� correct orientation of support faces (for breakaway and RHS supports);

� vertically straight - check in two directions on length of support with level (Figure 6.1);

� tops of supports even;

� support length correct.

FIGURE 6.1



66

6.5 EXCAVATION OF FOUNDATIONS

Depth and diameter of the foundations are part of the design information. This information shouldbe confirmed on site by examining the foundation material. Standard Drawing SD1363 shows thegeneral categories of foundation material and required excavation depths. (Refer Table 2).

For fixed supports, it is possible to increase or decrease the depth of excavation if conditions aresignificantly different from the design assumptions, however, If the conditions are better thanallowed for in the design, the footing should not be decreased.

If the conditions are worse, and the supports can be adjusted without affecting the performance ofthe sign and sign supports, then use the information given on Standard Drawing SD1363 todetermine the required foundations.

Foundations can be excavated by hand or auger. Loose material should be removed from theedge. A minimum of 75mm cover is required from the base of the excavation to the bottom of thesign support.

The concrete can be poured and compacted directly against the sides of the excavation, but forsandy conditions a cardboard or suitable liner should be used.

6.6 PREPARATION OF SUPPORTS

Rigid supports are erected and concreted into place in one piece. For smaller sections, thesupport can be cut to the required length. For larger sections, and breakaway supports, the levelof the excavation must be checked to ensure that the support lengths are appropriate. Minordifferences can be allowed for by adjusting the depth of the excavation.

Corrective action will be required if any of the following are encountered, refer to Figure 6.2:

(a) concrete cover from base of excavation to base of support less than 75mm;

(b) slipbase centreline exposure greater than 100mm;

(c) sign brackets affecting fuse plates or below fuse plates;

(d) top of supports higher than top of the sign;

(e) minimum clearance restraints not met. For breakaway supports 2.1 metres. For others, as persite and design conditions

(f) support below level of top bracket;

(g) depth of concrete less than specified;

(h) performance of the slipbase affected

At this stage, the following checks should be made and further corrective action taken wherenecessary:

� location of the fuse plates;

� straightness of the slip base plates; and

� straightness of the supports.

Note: Corrective action will be much more difficult once the foundations have been poured and the sign face erected.



66

FIGURE 6.2 PREPARATION OF SUPPORTS

6.7 INSTALLATION OF SIGN SUPPORTS

6.7.1 Foundations (poured concrete)

The requirements for foundation depth and radius are specified on the design plans or asordered.

Foundations are detailed on Standard Drawings SD1363 and SD1368, Appendix D. Typically, thefoundation comprises concrete poured into a bored hole. In concrete medians the depth anddiameter can be reduced, especially for the smaller signs. For larger signs it is recommended thatin all cases, the specified depth and diameter be used.

For non-breakaway supports, the support is embedded in the wet concrete. For breakawaysupports either the stub or the fully assembled breakaway supports are embedded.

For non-breakaway and fully-assembled breakaway supports the following are required.

(1) 75mm concrete fill between the bottom of the support (or stub) and the excavated hole;

(2) placement of the slipbase clear of the top of the concrete level (including allowance for boltends. Top of slip base not to exceed 100mm above ground level); and

(3) supporting gig, to ensure that the support remains in the correct location.

6.7.2 Erection of supports

For larger supports, a crane may be required to lift and hold the support in position while theslipbase bolts are installed, or held until propped, if still to be concreted in.

The support should be plumbed and correctly aligned before and after erection. The use of morethan two washers in a slipbase for levelling purposes is not recommended, as they could affectthe slipbase action.

Leveling problems are due to:



66

(a) insufficient care in the installation of the stub; and/or

(b) faulty manufacture (should be detected at the support preparation and inspection stage.

Pre-checking for such problems will avoid delays in field installations.

6.8 SUPPORT FINISHING

Before erection, check the operation and finish of the sign panel as follows:

(1) tighten slip base bolts as per instructions on SD1364;

(2) seal slip base as per instructions on SD1364

(3) check orientation of supports;

(4) check location and orientation of fuse plates;

(5) check location of slip base and potential operation;

(6) check clearances; and

(7) check supports are level at top.

6.9 ERECTION OF SIGN FACE

6.9.1 Small signs

Provided that due care and attention is paid to Workplace Health and Safety Regulations, smallsigns can generally be manhandled and erected using ladders. In most cases, if the sign does nothave stiffeners, it is small enough to lift from the ground by one person.

6.9.2 Larger sized signs

For larger signs, erection from the back of a truck, cherry picker or crane are recommended.Plank board signs can normally be erected by two men on separate ladders, or cherry pickers.

6.9.3 Flanges

For ease of erection, some supports can have a flange as per SD1365. These are not normallyrecommended as they do not allow the possibility of small level adjustments to suit siteconditions.

6.9.4 Lifting of the sign face

Sign faces are most vulnerable when a crane or other device is being used to lift the sign intoplace. The common practice of using saddle brackets attached to a stiffener is not recommendedfor the following reasons:

(a) excessive tension or stress on the stiffener;

(b) stressing of the saddle bracket; and/or

(c) possibility of fastener failure.

The use of a lifting bracket, such as that illustrated in Figure 6.3, is recommended for all liftingpurposes. The bracket spans two stiffeners thereby reducing tension and stress to any individualstiffener.

In other situations, the sign face might be supplied with timber stubs that will help to stiffen theface during erection.



66

FIGURE 6.3 LIFTING BRACKET (AS USED BY SE REGION RTCS)

6.9.5 Erection of a sign from the ground

All signs should be carefully rotated to a vertical position before lifting. At this stage, joins andcover strips are stressed if handled incorrectly and the structural strength of fastening could bereduced.

The timber stubs supplied with the sign face should remain on the sign face of the larger signs(see delivery of the sign face). The location of the timber stubs and the lifting brackets should bechecked to ensure that they do not interfere with the supports or brackets required to attach thesign face to the supports.

Stubs and lifting chains should not be removed until all brackets are attached.



66

6.10 SIGN CHECK LIST

6.10.1 Sign design checklist

Refer to steps in Appendix B.

6.10.2 Materials checklist

Sign panel Yes No

1) Sign Face details correct? � �

2) Sheeting class correct? � �

3) Manufactures sticker in correct place on rear LHS? � �

4) Date and manufactured stamped on RHS? � �

5) Timber stubs fitted and in place (if appropriate)? � �

6) All parts numbered and identified? � �

7) Any missing parts? � �

8) Rivets painted in correct colours? � �

9) Any obvious transport or manufacturing damage? � �

Stiffeners

1) Correct quantity? � �

2) Correct type? � �

3) Correct location? � �

4) Stiffeners attached correctly? � �

Joins

1) Cover strips in place? � �

Brackets

1) Correct size? � �


3) Size and quantity of nuts and bolts correct? � �

Supports

1) Correct size? � �


3) Correct length? � �

4) Identified and numbered? � �

5) Correct location of fuse plates? � �

6) Slip plates correct? � �

7) Size and quantity of bolts and washers correct? � �



66

6.10.3 Erection checklist

Sign location Yes No

1) Sign Face details correct? � �

1) Location confirmed? � �

2) Offset correct? � �

3) 5% orientation? � �

4) Sign suitable for terrain? � �

Sign Support Location

1) Correct number of supports? � �

2) Correct spacing of supports? � �

Foundation

1) Correct depth? � �

2) Correct diameter? � �

3) Correct level? � �

Supports/Stubs

1) Level? � �

2) Baseplates level? � �

3) Vertically plumb? � �

4) Correct length? � �

5) Correct spacing? � �

6) Sealed? � �

7) Correct bolt tensioning (torquing)? � �

8) Correct orientation (face)? � �

Erection

1) Correct sign ground clearance? � �

2) Brackets on all stiffeners? � �

3) Sign clear of fuse plates? � �

4) Correct sign face? � �



66

6.10.4 Sign erection check sheet (larger direction signs)

Job:.............................��..

Location: ��.. ..................... Sign Number: .�.��; �.�.�; ��..

Sign Number Stiffener No. Spacing Depth

5A 2A 5 450 1000

5B 2A 2 400 3000

5C 2A 3 500 1800

Supports 4 @ 80 NB

Length Slipbase Stub Length Foundation Depth ø

1 3045 Yes 200 900 450

2 3085 Yes 200 900 450

3 3165 No No 900 450

4 3200 No No 900 450

Spacing Comment

1-2 1500 Reduced spacing

2-3 1500

3-4 1500

Brackets 80 NB

Sign 5A 20

Sign 5B 8

Sign 5C 12

Yes No Yes No Yes No

All attached? � � Additional? � � Clear of fuse plate? � �

Fuse Plates

Yes No Yes No

Comment? � � Problem? � �



66

6.11 EQUIPMENT CHECK LIST

Location: Measuring tape

Plans

Excavation: Auger

Shovels

Crowbar

Foundations: Crane, or lifting mechanism

Concrete

Template

Measuring tape

Support preparation: Pipe cutters

Measuring tape

Erection: Crane or lifting mechanism

Keeper plate

Bolts/washers

Support Finishing: Torque wrench

Sealant

Sign Face Erection: Lifting brackets (2)



66

SECTION 7. SIGN FOUNDATIONS

7.1 CIRCULAR FOUNDATIONS

Sign supports should be set into concrete footings.

Footing dimensions are specified for two general soil strength categories, for both cohesive claysoils (firm to stiff and stiff to hard) and cohesionless sand soils (loose to medium-dense anddense). The majority of foundations will be in cohesive clay soils.

Footings in cohesionless sand soils are deeper and narrower than for cohesive soils, as lateralresistance is dependent on overburden pressure which increases with depth.

Both Simple Field Identification procedures and laboratory test parameters are suggested fordefining soil category.

Very soft or swampy soils are not acceptable foundation conditions for the footing dimensionstabulated. Where sound rock is encountered, it is likely that a pad footing, with or without rockbolts, or passive tension dowels will be the most appropriate foundation. These footings shouldbe individually designed.

Recommended

Posts in Sleeves are only appropriate for small posts up to 50mm nominal bore.

Larger single posts can use the same details as for multiple posts.

Design Guide for Roadside Signs Sign Foundations


77

SECTION 8. SIGN SUPPORTS

8.1 POST SIZE AND SELECTION

A graphical method of post selection is used in this guide, similar in format to that used inAS1742.2-1994. Each geographic wind region is catered for with a separate table for clarity andease of use. The post size is chosen directly from the table for a given sign size, height andnumber of posts. An option is given for either CHS, RHS posts or trusses.

8.2 SINGLE POST SIGNS

8.2.1 Signs up to 950mm wide

Standard regulatory, parking, warning and guide signs up to 950mm wide are generally erectedwithout panel stiffeners and are supported on a single post. Sign panels greater than 700mm wideand 1000mm deep are sometimes prone to twist and panel deformation. For this reason,consideration should be given to stiffening with Type 1 panel stiffeners (refer to Section 5.1.3).

Boltholes should be provided in sign panels up to 950mm wide and 1000mm deep.

The suggested rules for boltholes are listed in Table 8.1.

TABLE 8.1 HOLE SPACING FOR SIGN BLANKS

Sign Width Sign Height Number and Spacingof Holes

<950 <250 1

<950 <350 2@200

<950 <550 2@300

<950 <800 2@500

<950 <1000 2@750

This assumes even vertical hole spacings of 200, 300, 500 and 750mm. Previous StandardDrawings used vertical hole spacings of 205, 305, 510 and 735 to match imperial flattened postsType B and C as specified on the superseded Standard Drawing 1300.

It is recommended that flattened posts not be used. However, if refitting existing signs to theexisting flattened posts than the spacings in Table 8.2 must be specified when ordering.

TABLE 8.2 HOLE SPACING FOR IMPERIAL FLATTENED POSTS

Sign Width Sign Height Number and Spacingof Holes

<950 <250 1

<950 <350 2@205

<950 <550 2@310

<950 <800 2@510

<950 <1000 2@735

Sign Supports Design Guide for Roadside Signs


88

8.2.2 Sign posts

For standard regulatory, parking, warning and guide signs refer to Drawing No. 1368 for typicalbrackets used. Flattened posts with corresponding holes are no longer in general use in mostdistricts and brackets are recommended instead.

For signs less than 1m² in area, the post size is generally 50NB x 3.2mm CHS. Refer to AppendixB for determination of post sizes suitable for larger signs or heights.

Single posts will generally be CHS, although RHS should be considered for larger signs toincrease resistance to twisting.

8.2.3 Fittings

Standard Drawing No. 1369 shows several basic types of fittings referred to as Fittings B1, B2, B3,and B4. These are only for 50 NB posts and are a basic standard only. Alternative brackets andvariations on these themes are readily available and in most cases equally effective. The user willhave to consider their individual requirements before selecting a bracket for a particular purpose.Brackets for 65 NB are available but will not normally be required.

Fittings B1 & B2 are generally used for the erection of single sided standard signs.

Fitting B3 is used to erect back-to-back standard signs on a common post.

Fitting B4, wing saddle brackets, are used for single sided signs. These brackets provideresistance to movement but require site drilling of the post.

8.2.4 Signs over 950mm wide

For sign faces over 950mm wide the use of multiple support posts is generally recommended toavoid panel twist due to vandalism or wind buffeting. For situations where a two post support isnot possible (eg. narrow urban median strips), a single post may be used with panel stiffenersfixed in accordance with SD No. 1368 for signs up to 1800 wide. Refer to Appendix B for thedesign procedure.

If breakaway posts are required (refer to Clause 8.3.4), the slip base detail given on SD No.1368 isrecommended for single post signs subject to impact from any direction. The fuse plate detail isunnecessary and should not be used with single post signs.

Brackets are available that resist twisting, such as the Signfix Type 5 Bracket.

8.2.5 Posts in sleeves

There are certain situations where it is advisable to install the post into a sleeve inserted into thefooting, such as:

1. Where a sign is located on an urban median strip where it may be struck frequently.

2. Where it may need to be removed occasionally, to accommodate the swept path of over-dimensioned vehicles when turning.

This arrangement is only appropriate for small posts up to 50mm nominal bore.

Details of a typical sleeve assembly are presented in Drawing No. 1368 (Appendix D). Analternative assembly called the �loc Socket� is also shown on SD 1368. This is a commercialproduct and variations on the basic theme are just as effective.

8.3 MULTIPLE SUPPORT SIGNS

For sign widths greater than 950mm, panel stiffener rails are attached to the sign face andconnected to two or more supports. (Refer to Section 8.2.4 for discussion of the single postalternative).

Design Guide for Roadside Signs Sign Supports


88

The term support here refers to a CHS post, RHS post, or a truss support. This guide may beused for signs up to 8m in height and up to 7.5m in width, with a maximum area of 40m².

8.3.1 Panel stiffener rails

Two panel stiffener sections are used in fabrication of signs greater than 950mm in width, Type 1and Type 2A. Refer to TC9382 for specification of aluminium extrusions.

Stiffener type and number is specified in Appendix B, Tables B.1.1 and B.2, for a particular signwidth, height and location. Table B.1.1 presents three options for choice of stiffener type andnumber of supports:

Option 1

The most economical option using a minimum number of supports spaced at the standardspacing of 60% and 35% of sign width for 2 and 3 support signs respectively.

Option 2

This alternative arrangement may be adopted where an additional support is used to achieve�frangible� section sizes. Note the limitations on support spacing to achieve a satisfactory�frangible� solution. This option maintains the standard support spacings.

Option 3

An option for signs requiring two widely spaced supports, eg. straddling a footpath, where theminimum overhang is 10% of sign width.

For sign widths less than the tabulated limits, the support spacing may be reduced below thestandard spacing ratio to suit the site conditions, however the maximum stiffener overhangspecified in Table B.1.2 must not be exceeded.

Deviation from the specified stiffener/support arrangements will require calculation of width limitsin accordance with the appropriate formulae.

General constraints on stiffener arrangements are as follows:

� 500mm maximum stiffener spacing; and

� 150mm maximum panel overhang between stiffeners and top and bottom of sign.

For large signs erected using modular panels, refer to Section 5.

8.3.2 Sign supports

Tubular steel posts are used to support the stiffened sign panel, either Circular Hollow Section(CHS) or Rectangular Hollow Section (RHS). For larger signs, truss supports can and may have tobe used instead of CHS/RHS posts.

The number of supports and options for support type (RHS/CHS) are determined from theProcedure in Appendix B. The selection of support type is influenced by the followingconsiderations:

CHS has generally been the preferred post type due to:

� Availability as pregalvanised (300g/ms), which saves the cost and inconvenience of hot dipgalvanising RHS;

� Less wastage in fabrication due to 6.5m length stock sizes compared to 8m for RHS;

� Less tolerance on length required due to ease of pipe cutting and capping on site;

� Less tolerance on alignment with sign face required;

� Availability of fittings; and

� More easily realigned if bent over by wind or vehicle impact.



88

RHS posts are significantly more efficient than CHS as structural sections, particularly with thebenefit of availability as Grade C350/450.

In regions of Mild and Moderate Atmospheric Classification¹, advantage may be taken ofpregalvanised (100g/ms) RHS which has recently become available for sizes up to 125 x 75 and ishalf the cost of equivalent capacity galvanised CHS. This cost saving should be consideredagainst the erection advantages of CHS.

Note: ¹ Atmospheric Classification is as defined in AS2312 with Moderate zones having rainfall less than 1000mm p.a.,average humidity 50 to 80%, and being situated further than 15km from the coast with only light industrial activity.

In urban areas, the likelihood of corrosion from dog urine should also be considered. Althoughurine will attack all levels of galvanising, the heavier hot dip galvanised coating will give greaterprotection to the steel.

Posts for signs located in �high risk� areas which are �non-frangible� (refer 8.3.4), must be hot dipgalvanised after fabrication of slip baseplate and fuse plate hinge details as specified in SD No.1365 (refer Appendix D). The cost and convenience benefits inherent in having CHSpregalvanised are therefore removed and the cost savings of RHS, as discussed above, should beconsidered.

Posts in sleeves (refer Section 8.2.5) must be CHS posts.

A truss support comprises two CHS posts, or legs, connected together at a spacing 'S' by smallerCHS web members zig-zagging down the length of the posts (refer to SD No. 1366). Trusses aremore efficient than RHS posts as structural members, provided a limit (2.5m in this Guide) isplaced on the sign ground clearance of the signs they support (to prevent buckling). For largersigns, in certain locations, truss supports may be the only support type which can be used.Additionally, truss supports may have more aesthetic appeal than large CHS/RHS posts as theyrepresent a more efficient, refined design.

8.3.3 Aternative post section sizes

Table B.5 presents some alternative post section sizes for CHS posts to those called up in TableB.4. These alternative post section sizes are not applicable to trusses. The preferred sizes, basedon structural efficiency and availability, are highlighted in Table B.5.

8.3.4 Breakaway supports

The function of breakaway supports is to support the sign under normal wind load conditions, yetfail in a relatively safe manner when struck by a vehicle.

FIGURE 8.1 IMPACT PERFORMANCE



88

Breakaway supports are fabricated using RHS or CHS steel tube with both a slip baseplate and afuse plate hinge (except for single post signs). Failure occurs when the vehicle impact forceovercomes the frictional force between the baseplate and tension tearing of the fuseplate weld.Breakaway support details are designed to accommodate impact from both traffic directions, tocater for use in median strip and gore areas.

The slip base and fuse plate details are not required for small posts, which are considered to be�frangible� in collisions. Refer to Table 8.3.

TABLE 8.3 SMALL SIZE STEEL POSTS CONSIDERED AS FRANGIBLE

Likely Collision Speed Post Size, Nominal Borekm/h mm

<60 100

60 to 80 80

>80 65

Galvanised steel pipe posts up to 65 NB will rarely be found to cause injury to the occupants ofcars or heavier vehicles which collide with them. The same applies to low-speed urban typeconditions involving steel pipe up to approximately 100NB (RHS 75 x 50). For RHS, 75 x 50 postsmay be considered as �frangible�.

Consideration should be given to the use of an additional post that may reduce the required postsize to within the �frangible� limits. Increasing the number of posts is not a valid method forresultant post spacing less than 1.5m, due to the increased likelihood of collision with two posts.

To maximise road safety and minimise cost the intention should always be to locate signs in �lowrisk� regions where breakaway posts are not required.

�Low risk� regions are:

� Outside the Clear Zone defined in Section 4;

� Behind a guard rail or other barrier device; or

� At the bottom of a steep embankment or top of a steep cutting.

�High risk� regions are those within the Clear Zone defined in Section 4 which are not protectedby a barrier device or steep slope.

Breakaway Posts should be avoided where secondary accidents involving the impacting vehicleor dislodged pole and sign are significant. This is particularly relevant in urban areas wherepedestrians may be struck by falling pieces.

The standard design of large signs, usually situated within the Clear Zone, incorporate breakawaydetails in the truss support system.

To achieve satisfactory performance of the breakaway supports, the following criteria should bemet:

� The clearance of the sign above the ground should be a minimum of 2.1m to avoid penetrationof an impacting vehicle windscreen;

� Proper functioning of the slip base depends on control of clamping pressure between the baseplates produced by bolt tensioning. It is important for the specified bolt torque to be adheredto. The drawings specify shop assembly of slip bases, to minimise the inaccuracies of torquecontrolled bolt tensioning. Pre-assembled slip bases will also enable supports to be plumbedprior to pouring concrete footings.



88

� Large truss supports will often be difficult to erect prior to pouring footings. It is thereforedesirable to cast in the stub and then assemble the slip base on site. Special attention must begiven to the tensioning on site, with calibrated torque wrenches used and bolt threads keptclean.

� For CHS/RHS posts, the fuse plate hinges have been designed to resist 45% of the postmoment capacity. Signs with panel height ('B') greater than 165% of the clearance ('H') betweenthe ground and sign produce a bending moment which exceeds the fuse plate hinge capacity.For these signs the post size should be increased to the next section size. The allowable panelheight is then twice the clearance.

� For truss supports, the fuse plate hinges have been designed to resist 66% of the axialcompression capacity of their CHS posts/legs. Signs with panel height ('B') greater than 400%of the clearance ('H') between the ground and sign, produce an axial force which exceeds thefuse plate hinge capacity. For these signs, the truss size could be increased to the nextavailable size, though it must be noted that signs of this height would be outside the scope ofthis guide.

Breakaway Support details are presented in SD No 1365 for CHS/RHS posts and SD No. 1365and 1366 for trusses.

8.4 FITTINGS

8.4.1 Connection straps

Stiffener Rails are generally fixed to supports with circular or rectangular connection straps.

Galvanised steel connection straps for CHS supports (including trusses) and RHS posts aredetailed on SD 1364.

8.4.2 Erection cleats

To assist the erection of RHS posts, cleats may be welded to the posts to support the top stiffenerrail. Slotted cleats allow the sign to be levelled, as connection straps are fitted to the remainingstiffener rails. Erection cleats are detailed on SD 1364.



88

SECTION 9. STORAGE AND HANDLING OF SIGNS

9.1 GENERAL

In order for the sign to be effective, the surface of the sign must be free from damage, abrasion,dirt, oil or other markings causing loss of legibility.

These problems are especially severe when dealing with reflective material, since night-timelegibility is directly related to the quality and clarity of the reflective surface.

9.2 GENERAL STORAGE

Signs should be stored vertically on edge, either in a rack, or in such a way that they aresupported vertically.

Damage is likely to occur to signs stored in contact with each other, or banded together.

Signs stacked tightly together result in pressure points being induced on the reflective sheetingfaces, leading to areas not reflecting.

9.3 INDOOR STORAGE

Signs stored indoors may be left in their original transport packaging, provided that the storagearea will be maintained at a constant room temperature and is well ventilated. However, thebanding around any sign should be cut and removed.

If the storage area is a small, non-ventilated area, signs should be unwrapped from their transportpackaging (ie. cardboard, bubble wrap, etc) and only stored for relatively short periods.

9.4 OUTDOOR STORAGE

Signs stored outdoors must be unwrapped from their transport packaging and stored upright, onedge, using wooden battens on the floor, or as vertical supports, or both.

Signs stored outdoors, especially large direction signs, should be stored using a racking system,providing vertical support, avoiding pressure points on sign faces and allowing adequate aircirculation between sign faces to prevent a build up of moisture.

9.5 SIGN TRANSPORT

When transporting signs by truck or trailer, it is imperative that signs be securely braced vertically,and adequately supported and secured to avoid damage due to scuffing, abrasion and loadshifting.

Large direction signs should be braced using wooden stiffeners attached to the extrusions at theback of the sign, and transported with the stiffeners in place to avoid buckling and rivet popping.

9.6 SIGN ERECTION

Once signs have been transported to the road site, they should not be laid flat on the ground.Laying signs flat, can result in damage to the reflective face through direct contact with theground.

When attaching signs to posts, all connecting bolts should be tightened using offset spanners, notsocket wrenches. The use of offset spanners minimises tool and hand contact with the sign face andavoids scratching of the surface, as well as allowing the extent of tightening to be observed. Onlyone end of the nut and bolt should be tightened, preferable tightened from the rear of the sign.

Tightening from both sides can transfer stress into Class 1 Sheetings, with a top film resulting inpermanent pinwheel style wrinkles.

Storage and Handling of Signs Design Guide for Roadside Signs


99

Avoid over-tightening the connecting bolts, as this can cause specular glare from dimples on thesign face.

Nylon washers should be used between connecting bolt heads and the sign face, to protect thereflective sheeting from the twisting action of the bolt heads.

A circle of diameter slightly larger than the bolt head may be scored in the reflective sign face aroundthe bolt hole, to minimise any fine cracking that may inadvertently occur during bolt tightening.

When erecting large Direction signs, care must be taken to prevent lifting ropes, cables andchains from contacting the sign surface. These can cause permanent visible damage.

After installation, and before leaving the road site, inspect all signs to see that they have not beendamaged during erection and are free of oil and dirt residue from fingers and tools. A nightinspection will confirm that the surface has not been damaged.

9.7 SIGN COVERING

Covering signs is not recommended. If it is necessary to cover a sign face temporarily aftererection, caution must be exercised, as some coverings may cause permanent damage to thesign face following exposure to moisture and sunlight.

Porous cloth covers, which are folded over the sign edges and secured to the back of the sign,have been used successfully for limited periods.

Avoid the use of ropes, wire fasteners or strapping that may abrade the sign surface. Do not applytape to the sign face, as sunlight will cause it to bond permanently. Premask, or application tapemust be removed before exposure to sunlight.

Do not use paper or plastic covers, as heat and moisture entrapment can cause permanentdamage to the reflective sheeting on the sign face.

9.8 SIGN CLEANING

For maximum performance, signs should be kept clean and free from dirt, road tar, oil, bituminousmaterial and mulch. Primarily, this means cleaning the surface of the reflective sheeting - theessential characteristic of a sign.

A wet, detergent type, non-abrasive cleaner suitable for high quality paint surfaces isrecommended. The cleaner must also be free of strong aromatic solvents or alcohols and bechemically neutral (ie. pH of around 7.0). Following use of any cleaning agent, the sign surfacemust be thoroughly and immediately rinsed with clean water. In all cleaning operations, care shouldbe taken not to abrade the sign by use of stiff-bristle brushes or by unnecessary scrubbing.

Normal Cleaning Procedure:

1. Flush the surface with clean water to remove loose, dirt particles. A squeeze (or triggered) hosenozzle is convenient for this purpose;

2. Wash the sign face with a rag or sponge using a suitable detergent or commercial cleaner.Wash thoroughly from the top down. Once suds have been applied, keep a steady stream ofwater flowing on the sign face to wash away dirt particles;

3. Rinse the entire sign face with clean water, and allow the sign to drain dry;

4. Take extreme care in cleaning screened sign faces since some cleaning solvents may damagethe screen print.

Use a mild solvent such as mineral spirits for cleaning the sign face. Follow with detergent andwater, then rinse with clean water.

Avoid high-pressure sprayers. Do not direct sprays at sign face edges.

Design Guide for Roadside Signs Storage and Handling of Signs


99



99

APPENDIX A: TraSiS

TraSiSTraffic Sign Structures Version 2.0

TraSiS is an electronic implementation of the structural design procedures outlined in the 2001edition of the Design Guide for Roadside Signs. Our newest upgrade includes additional featureswhich greatly enhances the sign support structural design task. It replaces the Sign Design On-Line Software.

The software automates the design procedure and utilises the following inputs:

� Sign size;

� Terrain cross-section;

� Use of frangible or non-frangible supports;

� Selection of wind region (in accordance with AS1170.2); and

� Foundation strength.

A detailed or summary output is provided, and includes:

� The type (CHS/RHS) and number of supports;

� Support section details (including variable wall thickness for different grades of steel);

� Stiffener type, spacing and number of brackets; and

� Footing details.

A significant enhancement to the previous version of the software is the addition of a clear zonemodule, which calculates clear zone distances based on the following variables:

� Annual Average Daily Traffic (AADT);

� Horizontal alignment;

� Speed environment; and

� Terrain cross-section.

The user can consequently specify frangible or non-frangible support, contingent upon the signlocation.

For further information contact Principal Engineer Traffic.

Design Guide for Roadside Signs Appendix A


AA

Appendix A Design Guide for Roadside Signs


AA


APPENDIX B: DESIGN PROCEDURE FOR ROADSIDE SIGNSUPPORT

Step 1

Determine sign size - refer to Section 3.

Step 2

Determine Geographic Wind Region, A, B, C or D - refer Figure B.1.

Note that for exposed locations (unshielded Terrain Category 2 in AS1170.2) prone to high wind,or where support collapse is more hazardous than normal situations, a Wind Region one step upfrom that derived from the appropriate Table B.3 should be used for stiffener and support designin Step 5 and 6 (eg., use Region C values for Exposed Region B).

For exposed locations in Region D, a support size one size up from that derived from the graphshould be selected, or an additional support of the same size used.

Step 3

Determine if the sign has high or low risk collision exposure (refer section 8.3.4). Signs with highrisk exposure may require breakaway support details if the posts are not of frangible size. Signground clearance �H� for sign supports with breakaway details should be no lower than 2.1m.

Step 4

Determine if the sign requires a truss support. All truss supports require breakaway supportdetails and should have a sign ground clearance �H� between 2.1m and 2.5m. If the sign groundclearance exceeds 2.5m, Type B trusses with leg spacing S=1000 should be adopted. Signground clearance should generally never exceed 3.25m for truss supports.

Step 5

Select panel stiffener type and number of supports (N) from Table B.1.1, based on the sign width.For modular sign panels, use only Type 2 stiffeners.

Maximum sign widths are tabulated for 3 options of support spacing, as discussed in Section 8.Option 1 will be most frequently adopted for normal situations. Option 2 may be adopted wherean additional support is required to satisfy the Design Tables B.3, or is used to achieve �frangible�section size, and Option 3 caters for widely spaced supports (eg. straddling footpaths). Note thatfor signs of width less than the limiting values, support spacing may be reduced to less than the�standard� spacing provided that the maximum stiffener overhang specified in Table B.1.2 is notexceeded.

Select the number of panel stiffeners from Table B.2. For modular sign panels, use 3 stiffeners(Type 2) at 580mm spacing per 1200mm high sign panel module.

Step 6

Select the support (size and type) from Table B.3 for the appropriate Region A, B, C or D and signarea (10m², 28m² or 40m²). If no choice of support size is possible for the number of supports �N�chosen in Step 5, then add an extra support to �N� and choose a support size again from TableB.3. Refer to discussion in Section 8 of the text on the criteria for selection of support type (CHSPost, RHS Post or Truss Support) eg. requirement for breakaway supports, corrosion protection,erection, structural efficiency, cost, aesthetics.

Design Guide for Roadside Signs Appendix B


BB

For breakaway supports, note the limitation on sign panel height relative to sign ground clearanceheight. For signs supported by CHS/RHS posts, with sign panel height �B� greater than 1.65 xclearance �H�, increase the post size as indicated on Table B.3. For truss supports, this limit isincreased to 4.0 x clearance �H�, which should cover the largest signs to be erected.

For truss supports, note that Type A (S=750) trusses are to be used for sign clearance less than2.5m and Type B (S=1000) trusses for sign ground clearance up to 3.25m.

Step 7

Footings - Refer to Table B.4 for the selection of foundation strength category, based on eithersimple field identification methods or soil parameters determined by laboratory tests. Note thatfootings for sound rock or very soft or swampy ground conditions require individual design.

Step 8

Refer to Drawings in Appendix D for details of fabrication and erection.

FIGURE B.1 GEOGRAPHIC REGION

Hobart

CanberraSydney

Brisbane

Melbourne

Adelaide

303

Region A

Region B

Region C

Region D

0

25

20

25

Perth

Green HeadGunyidi

Morawa

Mullewa

Gallathard

Gascoyne Junction

Mt Amy

Millstream

Marble Bar

Onslow

Croydon

Pt. Hedland

Broome

DerbyWyndam

Ivanhoe

Adelaide River

Katherine

Borroloola

Burketown

West Moreland

Weipa

McDonnel

Moreton

Dunbar

Atherton

Cooktown

Cairns

Mareeba

Townsville

Bowen

Mackay

Rockhampton

Bundaberg

Maryborough

CasinoToowoomba

Glen Innes

Goffs Harbour

Grafton

Corindi

Emerald

Biloela

Monto

Charters Towers

Alice Springs

Collinsville

Carnarvon

Geraldton

Darwin

Appendix B Design Guide for Roadside Signs


BB

Table B.1.1 Stiffener Type and Number of Supports

OPTION 1 � Minimum No. of Supports; Standard Support Spacing

Panel Stiffener Type Type 1 Type 2 Type 2

No. of Supports (N) 2 2 3

Maximum Sign Width Region A/B 2.9m 5.6m 8.0m

(standard support spacing¹) Region C 2.9m 4.75 6.3m

Region D 2.9m 4.0m 5.3m

OPTION 2 � Additional Support; Standard Support Spacing



Maximum Sign Width Region A/B 4.7m 9.6m 5.5m

(standard support spacing¹) Region C 3.7m 7.6m 4.4m

Region D 3.0m 6.4m 3.6m

OPTION 3 � Minimum 10 % Sign Overhang



Maximum Sign Width Region A/B 1.8m 3.1m �

(10 % sign overhang) Region C 1.45m 2.55m �

Region D 1.2m 2.1m �

¹ support spacing may be reduced for signs of width less than tabulated limits provided maximum stiffener overhang specified inTable B.1.2 below are not exceeded.

Table B.1.2 Maximum Stiffener Overhang

Panel Stiffener Type Type 1 Type 2

Maximum Stiffener Overhang Region A/B 0.7m 1.2m

Region C 0.55m 0.95m

Region D 0.45m 0.8m

Table B.2 Number of Panel Stiffeners

Sign Height, B No. of Stiffeners(m) (Max. Stiffener spacing 500mm

Max. Sign Panel Overhang 150mm)

0.75 2

1.2 3

1.8 4

2.25 5

2.7 6

3.3 7

3.75 8

3.9 9



BB

SAMPLE CALCULATION

Step 1

Normal sign (single panel construction)

Sign width, A 4.8m

Sign height, B 2.2m

Sign ground clearance, H 2.0m

Location Moreton District, Rural Highway

Step 2

Region B, not exposed

Step 3

Low risk exposure as behind a guard rail - breakaway details not required.

Step 4 and 5

Table B.1.1 (Option 1) - Type 2 panel stiffeners with

2 posts for 4.8m panel width.

Table B.2 - 5 panel stiffeners required for 2.2m panel height

Step 6

In Table B.3.6 for Region B

Sign Area = 4.8 x 2.2 = 10.6m²

Height to Centre of Sign, H' = ground clearance height, H + B/2

= 2 + 2.2/2

= 3.1m

For 2 posts as determined in Step 4, interpolation of the design chart yields post choices of2/100NB CHS or 2/100x50x4.0 RHS.

For the Moreton District maximum corrosion protection is required so the RHS posts wouldrequire hot dip galvanising. Select 2/100NB pregalvanised posts.

Step 7

Choose foundation strength category in Table B.4, based on field identification or laboratorytesting.

Step 8

Refer to Drawings in Appendix D for details of fabrication and erection.



BB

For Modular Sign Panels, use 3 stiffeners (Type 2) at 580mm spacing per 1200mm high sign panelmodule (refer Figure 5.7).

Table B.4 Foundation Strength Category

COHESIVE CLAY SOILS

Strength Category Firm to Stiff Stiff to Hard

Undrained Shear Strength, 75 150Cu (kPa)

Elastic Modulus, E (kPa) 8,000 16,000

Subgrade Reaction Modulus, 30 60k (MN/m³)

Field Identification Effort is required to Only indented by thumb andpenetrate with thumb not possible to remould inor remould with fingers fingers without adding water

COHESIONLESS SAND SOILS

Strength Category Loose to Medium Dense Dense

Friction Angle 35 45

Elastic Modulus, E (kPa) 40,000 80,000

Coefficient of Modulus 3 9Variation, (MN/m³)

Field Identification No significant resistance Noticeable resistance toto excavation with spade excavation with spade orpenetration by crowbar little penetration by crowbar

Table B.5 CHS Post Section Equivalence Table

Post Section from Table B.3 Equivalent Post Section

CHS Grade Wall CHS Grade WallNominal Thickness Nominal Thickness

Bore (mm) Bore (mm)

*50 LIGHT C350 2.9 50 HEAVY C250 4.5

*65 LIGHT C350 3.2 65 HEAVY C250 4.5

*80 LIGHT C350 3.2 80 HEAVY C250 5.0

90 LIGHT C350 3.2 90 HEAVY C250 5.0

*100 LIGHT C350 3.6 100 HEAVY C250 5.4

125 LIGHT C350 3.5 *125 MEDIUM C250 5.0

150 LIGHT C350 3.5 *150 MEDIUM C250 5.0

Note: Not applicable to truss supports

* Indicates Preferred Sizes



BB

Table B.3.1 � Region A. RHS/CHS Posts: Sign Area ≤≤ 10m²



BB

Table B.3.2 � Region B. RHS/CHS Posts: Sign Area ≤≤ 10m²



BB

Table B.3.3 � Region C. RHS/CHS Posts: Sign Area ≤≤ 10m²



BB

Table B.3.4 � Region D. RHS/CHS Posts: Sign Area ≤≤ 10m²



BB




BB

APPENDIX C: COMPARISON OF 2001 DESIGN GUIDE WITH1991 DESIGN GUIDE

The 2001 Design Guide for Roadside Signs has been extensively revised from the 1991 DesignGuide for Road Signs especially the structural aspects. This appendix outlines the major changesand the reasons for those changes.

The guide now caters for signs up to 7.5m wide, up to 8 m high and up to 40m² in area.

There are now 3 tables for each wind region, with one table dedicated to the smaller signs(<10m²) and one covering larger signs of area 10m² to 40m² which includes truss supports.Trusses are an alternative for large signs in Regions C and D, and are a more structurally efficientalternative than RHS posts for sign areas around 20m² to 35m² in in any region.

1 INTRODUCTION

The 2001 guide has been developed from the 1996 Draft Edition which was released in responseto negative feedback from users of the 1991 guide and a perceived deficiency in the treatmentand explanation of breakaway posts. This feedback was confirmed in a user survey with manyrespondents indicating that the steel posts and footings derived from the 1991 guide to beexcessive to that required to support road signs. The survey indicated that users are adoptingalternatives to use of the guide including:

� Factoring of the 1991 guide Figure B2 to give less conservative post sizes;

� Use of the pre-1987 guide drawing TC9043 which uses steel yield as the allowable stress, 25year return period, old shape factor of 1.2 and no cyclone factor;

� Avoidance of breakaway posts by only using CHS for which there are no breakaway details;

� Posts are generally embedded into footings without reinforcement as detailed.

Users indicated a strong preference for accepting that some signs may be blown over in acyclone or storm rather than using larger posts which present an increased traffic hazard. It wasseen to be a relatively simple operation to bend smaller posts (particularly CHS) back into positionif blown over.

The survey also indicated a preference for use of CHS posts (as discussed further) for which therange of sizes and details are limited in the 1991 guide.

A limited field survey of road signs in Metropolitan District indicated that users are adopting postsizes and details in variance to those prescribed by the guide.

The incorporation of a rational method in accordance with Australian standards for derivation ofacceptable post sizes was considered critical for the success of the revised guide.

In addition to addressing the issue of post size/design wind load and breakaway post details theformat of the text and design procedure was improved to produce a clearer document.

The following discussion outlines the approach taken in the revised guide and identifiesdeficiencies in the 1991 guide.

2 DESIGN WIND PRESSURE

2.1 1991 Guide

The 1989 wind code Drag Co-efficient for hoardings of Cd = 1.5 was adopted in the 1991guidereplacing the 1.2 co-efficient used in the 1987 guide. This accounts for a 25% increase inwind pressure for all regions.

Design Guide for Roadside Signs Appendix C


CC

The 1987 guide divided the state into coastal and inland wind regions in accordance with the oldwind code. However, the 1.15 wind factor for cyclonic regions was not used in the design. The1989 wind code has replaced the 1.15 factor with Region C wind speeds. Region C wind speedsare accommodated in the current guide, representing a further 32% increase in wind pressure forcyclonic regions.

The 1991 guide particularly penalises inland regions by grouping together coastal region B withinland region A. This represents a 43 % increase in pressure for inland regions.

The 1991 guide incorporates a structural importance multiplier, Mi =0.9 in accordance with thenew wind code AS1170.2�1989. This factor is relevant to structures causing a low degree ofhazard to life and property (to be discussed further). The structural importance multiplier replacesthe use of lower return period winds used in the previous wind code. The 1987 guide does notappear to have adopted wind speeds of lower return period than 50 years, the typical designreturn period for buildings (compared to the 1981 drawing. TC9043 which uses a 25 year returnperiod). So, the use of Mi=0.9 reduces the pressure increase by 19%.

Comments have been made that road sign supports should not be designed like buildingstructures and that some �plastic� bending should be allowed to occur. Inspection of thecalculation file for the 1991 guide shows that intentionally or otherwise the steel yield stress wasused as the allowable stress, a method not in accordance with the AS1250 Steel Code uponwhich the design was generally based. This means that the posts would indeed bend if exposedto a design wind speed. This method may be a carry over from TC9043 which includes thecomment that �if allowable stress values are required, multiply Z values calculated by 1.5�. Use ofyield stress reduces post sizes by 40 % on that designed in accordance with the Steel Code.

2.2 New Strategy

From the discussion in 2.1 above it can be seen that, apart from the grouping of Region A withRegion B, the 1991 guide is not actually conservative relative to the Australian Standards, as areduced structural importance multiplier has been used and most significantly steel yield stresswas taken as the Allowable Bending Stress. How then can the post sizes be reduced in size with arational method based on the Australian Standards? The crux of the matter is the probability ofexceedence of the design wind speed which is considered acceptable. A higher acceptableprobability of exceedence produces smaller post sizes.

2.2.1 Structural Importance Multiplier

The structural importance multiplier, Mi in AS1170.2 represents a probability of exceedence of adesign wind speed. For Mi = 1.0 there is a 5% chance of exceedence of the Ultimate Wind Speedin a 50 year return period. For the current choice, Mi=0.9, the chance of exceedence in 50 yearand 1 year return periods is 25% and 0.5% respectively. The proposed importance multiplierwhich relates to the maximum acceptable chance of exceedence is Mi=0.75. For Mi=0.75, thechance of exceedence in 50 year and 1 year return periods is 96% and 6.5% respectively. That is,every year there is a 6.5% chance of the sign experiencing its design ultimate wind speed.

2.2.2 Directionality

AS1170.2 allows a directionality factor of 0.95 on wind speed in non-cyclonic regions foroverturning calculations to account for the reduced probability of the design wind speed occurringin the critical direction for a structure. It is proposed that this directionality factor is reduced furtherto 0.9 to account for the fact that (in non-cyclonic regions) the design wind speed will generallycome from one direction for a particular locality. As the design wind speed for a particular localitycomes from one direction, depending on the road orientation, some signs will never experiencethe design wind speed in their critical direction. Viewing the performance of the road signsstructures globally rather than designing for directionality in each individual sign justifies use ofthe reduced directionality factor of 0.9.

Appendix C Design Guide for Roadside Signs


CC

2.2.3 Regions

It is proposed that signs in the different geographic regions defined in AS1170.2 (A, B, C and D)are designed for the wind speed related to that region. This strategy alleviates the situation in the1991 guide where inland regions are grouped with Coastal.

2.2.4 Terrain Category

The 1991 guide adopts the AS1170.2 terminology for Exposed (Terrain Category 2) and General(Terrain Category 3 & 4) and uses a factor by which the post modulus is multiplied. It is suggestedthat this introduces a complexity in the interpretation of the AS1170.2 definitions which could leadto both under and over designed posts. The survey indicated that users will often choose the lessonerous General category for all signs.

Support sizes are chosen based on wind loads at locations which are assumed to be in thegeneral sheltered Terrain Categories, TC3 and TC4. The strategy selected is to go up one WindRegion rather than one support size now that an extra Wind Region D has been added to themanual. This strategy was found to be feasible and less conservative than just increasing thesupport size. Obviously, for exposed locations in Region D, this strategy is not possible and it isrecommended in these situations that the user should increase the support size.

2.2.5 Safe Failure

It is important that signs should fail by post bending prior to stiffener rails and panel fixing failureto prevent flying sign panels presenting a hazard. Stiffener rails are designed for the maximumdesign wind pressure with an additional safety factor of 1.67 to ensure signs are not blown offbefore the poles rotate. The factor 1.67 derives from the combination of load factor and capacityreduction factor on the pole (1.5/0.9).

Inspection of the 1991 guide indicated that whilst post sizes increased from the 1987 to 1991guides, the stiffener requirements were similarly derived, leading to a potentially unsafe failuremode.

2.2.6 Comparison of Various Guides

The example presented in the 1991 guide is used to compare the post sizes derived from theproposed new design with those derived from the current guide and other systems.

Example- sign area 6m², H�=2.5m, Region B, General terrain.

Table 1

It can be seen that for Region B there was no change between the 1987 and 1991 guide and thatthe post sizes in the Australian Standard are similar to the existing 1991 guide. The proposed newmethod produces sign posts significantly smaller than the current guide and other Australianguides in some situations.

Source Result

1991 guide 2/100NB

1987 guide 2/100NB

Victorian (1986) 2/100NB

TC9043 2/90NB

Australian Standard 1747.2 2/100NB

This guide 2/80NB



CC

2.2.7 Inclusion of Wind Region D

The guide now includes Region D to cater for the all Australian Standard wind regions and toprovide Exposed Region C design. The only special provision that had to be made for this Regionin the guide is the inclusion of one extra truss size. All details for RHS/CHS posts like stiffener/boltconnection, stiffener spacings, connector straps and rivets are still satisfactory for Region D.

3 DESIGN METHOD

3.1 Stiffener Arrangement

The proposed design method of the sign support structure removes the iterative approach used inthe 1991 guide such that the number of posts and stiffener type, spacing and no. are selecteddirectly for a given sign size. Variations to the standard post spacing are catered for by anadditional table for widely spaced posts and a table of maximum stiffener overhangs for reducedpost spacing.

Sign width limits are tabulated for the four geographic regions to be consistent with the postdesign method. The 1991 guide did not distinguish between regions for stiffener selection. Thiswould lead to either conservative or unsafe designs for some regions depending on the windpressure used in the stiffener design.

Table B.1 in the 1991 guide in attempting to cater for the range of options for stiffener type andspacing and no. of posts is both confusing, impractical and incorrect. Stiffener spacings as low as200mm are tabulated which is impractical for erection due to the number of fixings required. It wasindicated in the survey and verified by field inspection that signs with closely spaced stiffeners anda large number of fixing brackets had brackets inadequately fixed or missing altogether. For thelarger width of sign, the close stiffener spacings also produce post sizes which are not included inthe guide. Maximum post spacings are tabulated without consideration of the balancing ofcantilever overhang and span moments which is inherent in the method adopted from the 1987guide. For some tabulated values this produces excessive stress in the stiffeners. Consider alsothe incorrect specification of post spacing ratio for 3 post signs in the 1991 guide which producesdouble the allowable stiffener stress at the cantilever overhangs.

3.2 Post Size and Selection

A graphical method of post selection has been maintained in the new guide, similar in format tothe Australian Standard AS1742.2. Each geographic region is catered for with a separate set oftables for clarity and ease of use. The post size is chosen directly off the table for a given signsize, height and no. of posts. An option is given for either CHS or RHS posts for the smaller signs.Guidance for choice of CHS or RHS is presented in the text.

The benefits of the new method compared to the 1991 guide are:

� presentation of both CHS and RHS in one figure which both reduces the steps involved andallows direct comparison of options.

� no extra multiplication step for geographic region

� no confusion about sign area supported for signs with more than 2 posts.

� direct selection of posts with deletion of tables of post section module.

A section equivalence table has been added to the guide for CHS posts to offer alternative GradeC250 section sizes to those Grade C350 section sizes called up by the guide.

A table for RHS posts is not required since all post sizes called up by Table B.3 are available asDuragal Dual Grade C350/450 RHS.



CC

4 TEXT FORMAT

The text of the 1991 guide has clarified and revised to suit the new design method. The majormodification was to sort the discussion into Single Post and Multiple Post supports with aseparation of the standard Regulatory etc. signs from the signs requiring design of supports.Additional sections on Trusses, Modular signs and Plank board signs have also been included.

5 DRAWINGS

The Standard Drawings No SD 1363, 1364 and 1365 have superseded existing drawings 1360,1361 and 1362. The Drawings have been organised to cater for Breakaway and Non-Breakawaysupports together, rather than providing separate drawings with repeated details.

This assists in providing a less fragmented document. The slip base and fuseplate hinge aresimply additional details incorporated as required onto the standard post.

The revised drawings also present CHS and RHS posts together rather than on separate drawingswith inconsistent specifications.

Specification of clearances, heights, orientation etc. are referred to the MUTCD document ratherthan trying to incorporate some of this information on the structural drawings.

Drawing SD No.1295 has not yet been altered while drawings 1296, 1297, 1298, 1299, 1300 and1360 have been withdrawn.

6 AS4100 STEEL STRUCTURES CODE

The sign support posts have been designed in accordance with the new Limit State steel codeAS4100. Ultimate design wind speeds were used. Significant saving are possible for compacttubular sections with ultimate limit state design compared to the AS1250 allowable stress method.

7 BREAKAWAY POSTS

7.1 Text

The text has been clarified in the explanation of where and why breakaway posts are required. Inparticular the ambiguity of definition of �low� and �high� risk areas has been removed. Currently�low� risk is defined as outside the clear zone, and �high� risk is within half the clear zone distanceof the traffic lane edge of the road.

The term Slip Base Supports has been dropped in favour of Breakaway Posts as Breakaway Postsincorporate both a slip base and the fuse plate hinge.

7.2 Frangible Posts

The explanation of when posts are considered to be adequately frangible without theincorporation of breakaway post details has been expanded and revised. The size of postsconsidered to be frangible has not been modified in accordance with the Australian StandardAS1742.2. AS1742.2 nominates 80 OD and 114 OD as appropriate frangible sizes for high speedand low speed areas compared to 60 OD and 89 OD in the 1991 guide. The AS1742.2 figureshave been advised by the MS12 Committee who revised the AS1742.2 as being incorrect.

The size of posts deemed to be frangible seems to be a subject of some contention.

The choice is probably influenced by the issue of the liability of Authorities erecting potentialroadside hazards. Opposing the issue of liability is the requirement for economical provision of signsupports. It is noted that the Victorian Manual only nominates 60 OD posts and smaller as frangible.This compares to experience in the Central District Office that indicates impact with 114OD CHS in60 kph zones are survivable and advice from the Mackay District that 165 OD CHS safely collapsewithout slip bases. The Moreton District considers that 114 OD is the frangible size limit.



CC

7.3 Criteria

Criteria for satisfactory performance of breakaway posts have been included in the new guide.

The AASHTO Roadside Design Guide criterion for 2.1m clearance has been incorporated. TheAASHTO criteria on post weight will be satisfied for all posts in the range of the guide.

A minimum post spacing of 1.5m has been recommended as the limit for use of additional postsof �frangible� size to support signs in �high risk � zones. The AASHTO Guide considers all posts ina swept path of 2.1m when checking that the weight of posts is less than the recommended limit.Design in accordance with the AASHTO Guide would therefore require consideration of thecombined resistance to impact of all posts within a 2.1m width, rather than designation ofindividual posts as frangible if smaller than the recommended size. Adoption of a 2.1m swept pathwould disqualify many signs from use of �frangible� post support. The 1.5m minimum spacinglimit is proposed as an acceptable, less conservative, limit for consideration of impact on posts inisolation.

A limit on sign height relative to clearance has been incorporated to ensure that the fuse platemoment capacity is not exceeded under the design wind speed. The current fuseplate detailappears to be designed for the post capacity which relates to a sign height not greater than theclearance. Many existing signs will not conform to this criterion and will therefore potentially fail atthe fuseplate at less than the design wind speed.

7.4 Post type

Breakaway Post details have been incorporated for both CHS and RHS posts.

7.5 Details

The breakaway details used in the 1991 guide have been revised and enhanced as discussedbelow. It is intended that the performance under impact will be improved by the modifications,however testing of impact performance is recommended.

7.5.1 Slip Base

The slip base plates have been detailed to accommodate angled impact from both trafficdirections.

Bolt tensioning requirements have been revised to improve the performance of the slip basesunder impact. The current guide specifies the part-turn method of tensioning which is relevant tohigh strength friction grip bolts tensioned to the bolt Proof Load. AASHTO recommends clampingforces relative to post size for satisfactory slip base performance. Excess bolt tension increasesthe impact force transmitted to the vehicle. The clamping force recommended in AASHTO relatesto very low bolt tension which may cause problems of a loose connection, unserviceable for windloading. The proposed method is to torque the bolts to 100 Nm which is the torque adopted in thestandard Light Column drawing No. 1285. This torque relates to only 1/2 and 1/3 of snug tight forM16 and M20 respectively. AS4100 discourages the use of torque control of bolt tension in favourof load indicating washers due to inaccuracies from thread cleanliness, wrench calibration, threadtype and various other factors. However load indicating washers do not cater for low bolt tensionand inaccuracies in torque control can be minimised by oiling the threads and assembling thebaseplates in the shop prior to delivery to site. Shop assembly has the added advantage ofenforcing the plumbing of the posts prior to pouring concrete rather than casting in the stub belowthe slip base and then using shims between the baseplates (in the critical slip zone) to plumb theposts, as is currently specified in the guide. It is further noted that AASHTO recommends regularchecking of bolt tension for signs in service.

Bolts have been sized with an additional factor of safety to ensure post failure prior to bolt failure.This also recognises the cyclic loading and fatigue regime operable on the bolts.

Additional washers have been specified under the bolt head and nut to enable uniform pressureunder the head and nut with the slotted baseplates.



CC

The fillet welds of posts to baseplates have been corrected. The current guide specification showsfillet weld size increasing with overall post size rather than with tube wall thickness. The weld sizescurrently tabulated are generally not compatible with the post strength such that failure wouldoccur at the welds before post bending capacity was mobilised.

7.5.2 Fuse Plate Hinge

The fuse plate detail has also been modified to accommodate impact from both traffic directions.This has been achieved by use of a fuse plate on both sides of the post with a completeseparation/cut of the post.

The fuse plate detail has been increased in bending capacity to 45% of the post capacity toenable sign height to be up to 165% of clearance (refer to discussion in 7.3 above). This willaccommodate a greater range of signs than is currently possible (although not specified).

Field inspection along the Gateway Arterial Rd. indicated that the fillet weld size and length on thefuse plates are frequently less than specified on the drawings. Cracking was evident in some ofthese inadequate welds. These inadequate welds could significantly reduce the expected life ofthe posts, particularly as the welds are subject to cyclic wind gust loading and stressconcentration effects. Apart from a recommendation for improved Quality Control the detail hasbeen revised with thicker fuse plates to improve the chance of correct weld size. Thicker fuseplates also improve the transfer of wind shear across the cut post. Welding is now continuous allaround the fuseplates which will also alleviate stress concentrations. A smaller 3 or 4mm weld isspecified for the post below the cut to facilitate failure on impact.

The current galvanising procedure specifies for posts to be hot dip galvanised prior to welding offuseplate with weld damaged area cold galvanised subsequent to welding. This has beenspecified to ensure corrosion protection behind the fuseplate which is not sealed around theedges. Field Inspection indicated that posts are susceptible to corrosion along the cut edges andthe weld regions which are cold galvanised. The revised procedure specifies welding of thefuseplate prior to hot dip galvanising. Additionally, the post splice is specified to be full contactwhich should enable the galvanising to seal across the cut. The fuse plate is welded all around toeffectively seal behind the plate such that the whole assembly can be protected with the hot dipgalvanising.

8 POSTS TYPES

The user survey indicated a strong preference for the use of CHS posts rather than RHS.Advantages identified with CHS are pregalvanised, availability, cheaper (availability in 6.5mlengths c.f 8m for RHS leading to less wastage is one consideration), readily cut and capped onsite with pipe cutters so less tolerance on post length required, less requirement for alignmentwith sign face, availability of fittings and more easily pushed back to alignment if bent over bywind or vehicle collision.

The 1991 guide is deficient in the treatment of CHS posts, with tabulation for up to 100NB only.The new guide provides for CHS posts up to 150NB.

90 NB is included in the graphs but is not readily available. The current guide use of Grade 200steel for CHS has been updated to incorporate the new Grade 250 rating. Additionally, posts of100 nominal bore and smaller have been specified as Grade 350 �Light Gal�. The Grade 350 CHSare lighter, stronger and the same cost as the equivalent �Medium Gal� Grade 250 posts.

RHS posts have been retained with further explanation to when they may be economical. Thestructural efficiency and hence potential cost saving has been identified particularly with the use ofpregalvanised RHS. Tubemakers Duragal is only 3% more expensive than black steel and is ratedat Grade 450. The cost of a Grade 450 pregalvanised RHS post is 1/2 the cost of the equivalentstrength CHS. The use of pregalvanised RHS (without further hot dip galvanising) is limited toregions of low corrosion potential due to the reduced thickness of zinc coating (100g/m²compared to 300g/m² for hot dip galvanising).



CC

RHS posts may also be cost effective for Breakaway Posts where the advantage of pregalvanisedCHS is lost with the requirement on hot dip galvanising the Breakaway Posts after fabrication.

9 STIFFENER RAILS

A maximum stiffener spacing of 500mm with overhang of 150mm is proposed compared to the1991 guide maximum of 450mm spacing and 100 overhang. This saves 1 rail on the common signheights of 1200, 750 and 1800.

The 1991 guide specifies a pole spacing ratio of 0.2/0.3/0.3/0.2 and 0.2/0.6/0.2 for 3 and 2 polesigns respectively. The two post ratio is retained whilst the 3 post ratio is revised to the mosteconomical spacing ratio of 0.15/0.35/0.35/0.15. These ratios balance both pole load and stiffenersupport and span moment.

For the wider 3 post signs, the stiffener moment is very sensitive to the post spacing ratio. The20% overhang for 3 post signs in the 1991 guide produces double the stiffener moment producedwith the 15% overhang now specified. This means that stiffeners constructed in accordance withthe 1991 guide would be overstressed at the overhang.

The concept of utilising composite action between the sign panel and the stiffeners was proposedat a previous stage in the review process. The use of composite action was necessary to make thestiffeners work for the design wind pressures including a factor of safety to ensure safe failure(refer 2.2.5). The design wind pressure has been reduced further such that composite action isnot required. This is fortunate as composite action relies on the panels to be spliced with a coverstrip in accordance with the current specification. The field survey indicated that the splice coverstrip is frequently omitted.

10 SINGLE POST SIGNS

The current guide allows signs less than 950mm wide to be supported on a single post. The signpanel overhang for a sign of 950mm width is 475mm which is in excess of the maximum overhangdetermined by a stress calculation. This concession is presumably to cater for the historicaldevelopment of standard sign supports and is retained in the new guide. It is however highlightedin the text that the larger panels may be subject to twist from wind gusting and vandalism.

Drawing No. 1300 specifies 50NB posts for signs up to 1m². Depending on sign height, the postsize may not be in accordance with the design Table B.3. This is consistent with the reducedcapacity of the unstiffened sign panel bending capacity as discussed above.

A proposed addition to the guide is a new system and detail to accommodate the commonsituation of signs wider than 950mm which cannot be supported on 2 posts, for eg. on a narrowmedian strip. The sign panel is stiffened and fixed to a single post with 6mm steel brackets. Thesteel brackets are screwed into the post to prevent rotation. This detail is shown on SD No. 1368.

11 FOOTINGS

11.1 1991 Guide

A large discrepancy is noted in the 1991 guide between pier sizes for CHS (Drawing 1360) andRHS (Drawing 1362). For example the 114CHS requires a 1200 dp. by 250 diam with 20Mpaconcrete compared to 100x50RHS which requires a 1400 dp by 600 diam. with 32 Mpa concreteand reinforcement.

This discrepancy is due to the design method and soil lateral bearing capacities adopted. Thereare various methods commonly used for design of laterally loaded piers including UBC, Rutledge(U.S Outdoor Advertising Association) and Broms/Poulos (SAA Piling Code). The value of lateralbearing capacity used is dependent on the acceptable amount of movement to mobilise thatresistance.



CC

The 1991 guide for RHS sections appears to have used the UBC method with 60kPa/m lateral soilpressure. This is applicable to the design of footings for building in hard clay or well gradedsand/gravel. The CHS values can be derived from the UBC formula with lateral soil pressure of120 kPa/m. This indicates a lower safety factor on soil capacity and greater movement at groundlevel (hence pole rotation).

The use of the UBC method with soil values applicable to acceptable movements in buildingfoundations is over conservative.

It is further noted that the 1991 RHS footing sizes increased on the 1987 guide whereas the CHSfootings reduced on the 1987 guide sizes.

11.2 New Strategy

The new guide specifies footings sizes for two soil strength categories for both cohesive and non-cohesive soils. Cohesive and non-cohesive soils are distinguished between, due to differentmechanisms of soil resistance and hence design formulae. For non-cohesive soils, lateralresistance is dependent on overburden stress, so footings are deeper and narrower than forcohesive soils.

The new Table B.4 in the Appendix B design procedure enables choice of appropriate FoundationStrength Category by use of either simple Field Identification procedures or parameters derivedby laboratory testing.

11.2.1 Cohesive Soils

The footings for cohesive soils are designed using the method suggested by Coyle andBierschwale, �Design of Rigid Shafts in Clay for Lateral Load�, ASCE J Geotech Eng, Vol 109,No.9, 1983. This method determines the ultimate lateral load that can be applied to a pile for alimiting deflection criteria. A pile rotation of 2 degrees is considered to be the serviceable limitbeyond which loosening of the pile may occur due to plastic deformation of the soil. This methodproduces less conservative results than other methods which limit soil pressure.

11.2.2 Non-Cohesive Soils

The SAA Piling Code (AS2159-1978) was used for design of footings in non-cohesive soils with anappropriately chosen Factor of Safety on ultimate lateral resistance.

11.2.3 Other Soils

The guide highlights the requirement for special design of footings in very soft or swampy soilsand sound rock.

11.2.4 Details

The cast-in anchor bolt detail for non-breakaway posts has been deleted from the guide due tothe preference of users to simply embed the posts into the concrete footing. This also saves onfabrication and avoids damage to pregalvanised coatings.

The footings have been designed without reinforcement by utilising the combined bendingresistance of the embedded post and unreinforced concrete pier.

The diameter and depth of piers have been chosen with consideration to minimising pier depth.The survey indicated a requirement to minimise depth for avoidance of services.

12 SIGN DETAILS

12.1 Stiffener Connection Straps

The connection strap detail has been retained apart from some revision to the dimensions for RHSstraps. The RHS strap dimensions were tabulated such that there was no gap between the strapand stiffener to enable clamping of the stiffener against the post.



CC

Reference to aluminium post straps has been deleted from the guide due to inadequate strength.

Calculations indicate that the Type 2 stiffener has inadequate local bending strength at the 10mmbolt connection to the strap. The Type 2 stiffeners are subject to very high local bending stress atthe connection strap bolt. The calculations indicate overstress under the design wind load butthere may also be a problem of overstress from tensioning of the connection bolt. ALCAN inSydney have indicated that they make the extrusion to the Department specification and havenever performed any testing or design. A modified Type 2A section has been provided and isshown in TC9382 which has the same section modulus as the current type 2 and an increased lipthickness. This solves the problem of local bending weakness of the current Type 2.

12.2 Galvanising Vent Hole

The size of the vent and drain holes for galvanising have been modified in accordance with therecommendations of the Galvanisers Association.

12.3 Erection Cleats

The detail referred to in the 1991 guide as the �fused plate detail�, for hanging the sign off the topof the poles and then clamping is adopted by some users. This has been retained in the guide. Toavoid confusion with the breakaway fuse the new name, �Erection Cleats� has been adopted.

13 INCORPORATION OF TRUSS TYPE SUPPORTS

Truss supports have been proposed by the Gympie District office of Queensland Transport for usewith larger signs. An extensive check of their design has been carried out with a view torationalisation for incorporation in the Design Guide.

13.1 Design Philosophy

The design philosophy used in the calculations was to limit the inter-post spacing S for a trusssupport (Refer Drawing DS no. 1366) to the minimum of 750 mm where possible to allow greaterflexibility in matching the web member node spacings to the specified post height for a certainsign. This was not possible for Region D, which includes a truss size T3B which is a truss with80NB CHS posts at a post spacing S of 1000 mm. The choice of truss sizes was also rationaliseddown to six:

T1A (65 NB CHS posts, S=750), (C350, 3.2 m wall thickness);

T1B (65 NB CHS posts, S=1000), (C350, 3.2 m wall thickness);

T2A (80NB CHS posts, S=750), (C350, 3.2 m wall thickness);

T2B (80NB CHS posts, S=1000), (C350, 3.2 m wall thickness);

T3A (80 NB CHS posts, S=750) (C350, 5.5 m wall thickness); and

T3B (80 NB CHS posts, S=750) (C350, 5.5 m wall thickness).

T1, T2 and T3A are suitable choices for all Wind Regions while T3B is normally only used inRegion D.

13.2 Joint Efficiency and �Roark�s� Buckling

A truss support consists of two CHS legs or posts connected together with smaller CHS webmembers. The truss resists wind-induced bending by developing axial forces in the posts.Therefore, the moment capacity of the truss is proportional to the axial capacity, specifically thecompressive capacity, of its posts. Because of the complexity of the web connection to the posts,the normal axial capacity of the posts have to be modified slightly. There is some eccentricity inthe post axial force caused by the transfer of axial forces from the webs to the posts. This hasresulted from the reduction of pin diameter (which the web members are bent round at the webnodes) to 120mm to reduce the bending effects due to web force eccentricity at the nodes. Thus a



CC

joint efficiency factor of 0.8 has been used in design to modify the post axial capacity.

Because axial forces vary along the length of the posts to a maximum at the supported base, thecritical buckling load and thus the compressive axial capacity of the posts was modified further.�Roark�s Formulas for Stress and Strain� provided a factor of 1.25 for the modification of the axialpost capacity.

13.3 Compressive Leg Bracing and Effective Length for Buckling

The capacity of the trusses is very sensitive to the effective buckling length of the compression leg.

The truss legs fixed to the sign face provide an effective sway frame which limits out of planedeflection to less than 3.150% x Le under the action of the restraint forces. The unsupported trusslegs are therefore braced back to sign face legs.

A sign clearance limit of 2.5 m maximum is recommended for truss supported signs to keep thetrusses reasonably efficient. The capacity tables have been based on this limit. Exceedence of thislimit will significantly reduce the capacity of the trusses.

13.4 Breakaway Details

Breakaway Details are standard for the Trusses as recommended by the Gympie District to assisterection and because most large signs are located in the Clear Zone of high speed roads.

13.5 Footing Design

The truss footings have been designed taking into account a combination of effects including, pierbending, pad footing base bearing and side face shear.

14 MODULAR SIGN PANELS

Modular Sign panels have been included in the guide to facilitate the installation of larger signs. Asketch which details the general arrangement for these signs has been included in the guide.Each 1200mm high sign panel module is required to have 3 stiffeners at a set spacing of 580 mm.The guide design procedure for selection of supports for Modular Sign Panels is exactly the sameas for normal signs.

15 RECOMMENDATIONS

The following recommendations are made on items and issues which may require furtherinvestigation.

15.1 Frangible Post Size

As discussed in Clause 7.2 above, there are various opinions on the appropriate size limit onposts which may be considered as frangible. It has been recommended by Lance Christiansen ofthe Central District Office that the testing facility at the Rocla plant at Gailes be used to carry outsome crash tests to determine at what size post, breakaway details are required.

15.2 Breakaway Post Performance

The slip base and fuse plate hinge details were adapted from the method presented in theAASHTO Guide. There are however significant differences between the AASHTO method whichuses hot rolled I-beams and the QT designs which use RHS and CHS sections. The AASHTOGuide also stresses the importance of slip base and fuse plate clamping pressures. Although thebolt tension in the new guide has been significantly reduced from the 1991 guide it is still greaterthan recommended in the AASHTO Guide for the reasons presented. Conversely the bendingcapacity of the fuse plate hinge has been increased on that provided in the 1991 guide toaccommodate a greater range of sign configurations. The above discussions leads to therecommendation for inclusion of testing of breakaway post performance in any program of testingof frangible post limits.



CC

15.3 Fuse Plate Fabrication

As discussed in Clause 7.5.2, the welding of the fuse plate is critical for successful performanceunder both wind loading and vehicle impact. Based on the very limited field survey along theGateway Arterial Rd., it is recommended that an improved Quality Control procedure beimplemented on the fillet weld size and quality.

The galvanising procedure of the breakaway posts has been modified such that the posts arewelded after fabrication of the fuseplate. It is intended that the galvanising will seal across the postcut. Industrial Galvanisers have advised that they would undertake some trial galvanising of thefuseplate to confirm that the cut can indeed be effectively protected by the galvanising.

There is still a need to carry out vehicle impact tests to verify the performance of the slip base andfuse plate hinge. The use of the slip base and fuse plate for truss supports is carrying the concepteven further from the original AASHTO application and should be verified by impact testing.



CC

Appendix D: STANDARD DRAWINGS

Design Guide for Roadside Signs Appendix D


DD

Standard Drawing No. 1363 � Traffic Sign Support

500m

mm

ax.

stiff

ener

spac

ing

CH

S-

cap

with

appr

oved

galv

anis

edpo

stca

psor

aspe

rR

HS

treat

men

tsR

HS

-ca

pw

ith5m

mga

lvan

ised

plat

ebu

ttw

elde

dan

dfin

ishe

dflu

shw

ithto

pof

post

.Col

dga

lvan

ise

dam

aged

post

ifpr

egal

vani

sed

Post

cap

Fuse

plat

e

2.1m

min

.sl

ipcl

eara

nce

‘Hs’

Sig

nfa

ce

CH

Sor

RH

Sst

eelp

osts

(ref

erTa

ble

1fo

rde

tails

)

Post

embe

dded

into

conc

rete

foot

ings

150

max

.ov

erha

ng75

100

100

max

.

Alu

min

ium

pane

lstif

fene

rs(s

eeno

teG

3)

150

max

.ov

erha

ng

75co

ver

100

max

.ov

erha

ng

RH

Ssm

alle

stdi

men

sion

RH

Sla

rges

tdi

men

sion

Gro

und

leve

latf

ootin

gto

beco

nfir

med

prio

rto

fabr

icat

ion

ofpo

sts

10m

mø

galv

anis

edve

ntai

rho

lein

supp

orts

requ

ired

tobe

hotd

ipga

lvan

ised

.Loc

ate

diag

onal

lyop

posi

teve

ntdr

ain

hole

inba

sepl

ate.

Slip

base

(see

note

G6)

Sig

nhe

ight

‘B’

(see

note

G8)

Cle

aran

ce‘H

’(s

eeno

tes

G2

&G

8)

‘L’(s

eeno

teG

7)

‘d’

Slo

peco

ncre

tesu

rfac

eaw

ayfro

mpo

stat

1:6

A

1364

B

1364

B

1364

Erec

tion

clea

ts(n

otst

anda

rd)

(see

note

G5)

A

1364

E

1365

Fuse

plat

e

(see

note

G6)

D

1365

Sta

ndar

dpo

stsp

acin

g(s

eeno

teG

1)0.

60x

sign

wid

thfo

r2

post

s0.

35x

sign

wid

thfo

r3

post

s0.

25x

sign

wid

thfo

r4

post

s

REA

RELEV

ATIO

N(r

efer

tonot

eG

2)

SID

EELEV

ATIO

N

GEN

ER

AL

NO

TES

:

PO

ST

DIM

ENS

ION

S(m

m)

WA

LLTH

ICK

NES

S(m

m)

50N

B

65N

B

80N

B

90N

B

100N

B

125N

B

150N

B

2.9

3.2

3.2

3.2

3.6

5.0/

3.5

5.0/

3.2

3.0

4.0

3.0

5.0

5.0

5.0

C35

0

C35

0

C35

0

C35

0

C35

0

C25

0/C

350

C25

0/C

350

C45

0

C45

0

C45

0

C45

0

C35

0

C35

0

300

300

300

450

450

450

600

300

450

450

600

600

600

300

300

300

300

450

450

450

300

450

450

450

600

600

300

300

300

300

450

450

450

300

450

450

450

450

450

300

300

300

300

300

450

450

300

300

450

450

450

450

750

1000

1100

1200

1200

1350

1600

1100

1200

1350

1600

1700

2000

750

800

900

1000

1200

1200

1300 900

1200

1200

1300

1400

1700

450

700

900

750

900

1200

1300 900

900

1200

1300

1500

1800

450

500

600

750

700

800

1100 600

700

800

1100

1000

1300

75x

50

100

x50

125

x75

125

x75

150

x10

0

200

x10

0

GR

AD

E‘d

’(m

m)

‘d’(

mm

)‘d

’(m

m)

‘d’(

mm

)‘L’

(mm

)‘L’

(mm

)‘L’

(mm

)‘L’

(mm

)

FIR

MTO

STI

FFV

ERY

STI

FF

CO

HES

IVE

CLAY

SO

ILS

LOO

SE

TOM

EDIU

MD

ENS

E

CO

HES

ION

LES

SS

AN

DS

OIL

S

FOO

TIN

GS

(SEE

NO

TEG

4)

PO

ST

SP

ECIF

ICAT

ION

CH

S

RH

S

TAB

LE

1

CO

NC

RETE

NO

TES

:

C1.

Con

cret

esp

ecifi

catio

n:S

lum

p80

mm

Max

.agg

rega

te20

mm

Min

.cem

entc

onte

nt25

0kg/

mM

ax.w

ater

/cem

entr

atio

0.55

Con

cret

eN

25to

AS

3600

C2.

Mec

hani

cally

vibr

ate

full

dept

hof

conc

rete

.

C3.

Con

cret

epo

ured

dire

ctly

agai

nsta

uger

hole

3

STEEL

NO

TES

:

S1.

Ste

elgr

ades

(FY)

tobe

:

Sec

tion

and

plat

esto

AS

1204

-25

0Mpa

.

CH

Sto

AS

1163

-25

0/35

0/45

0M

pa,a

ssp

ecifi

ed.

S2.

Wel

ded

conn

ectio

nssh

allb

ew

ith6m

mco

ntin

uous

fille

tw

elds

inac

cord

ance

with

AS

1554

cate

gory

spec

ial

purp

ose

(SP

),us

ing

elec

trode

type

E48X

X/W

50X

MIG

wel

ding

orM

IGw

eldi

ngun

less

note

dot

herw

ise.

S3.

All

bolts

com

mer

cial

grad

eun

less

note

dot

herw

ise.

S4.

All

bolts

,fitm

ents

,pla

tes,

etc.

tobe

hotd

ippe

dga

lvan

ised

,U.N

.O.

S5.

Cor

rosi

onpr

otec

tion.

CH

Spo

sts

-pr

egal

vani

sed

300g

/m

RH

Spo

sts

-pr

egal

vani

sed

300g

/m

CH

S&

RH

Spo

sts

-ho

tdip

ped

galv

anis

ed30

0g/m

afte

rfa

bric

atio

nof

fuse

plat

ean

dsl

ipba

sepl

ates

.

Not

e:R

equi

rem

ents

for

vent

hole

sto

RH

Spo

sts

&C

HS

post

s.

Non

-bre

akaw

aypo

sts:

-

Bre

akaw

aypo

sts:

-

2 2

2

G1.

Sta

ndar

dpo

stsp

acin

gm

ustn

otbe

alte

red

with

out

appr

oval

ofpr

inci

pal.

Tabl

esin

the

Roa

dS

ign

Des

ign

Man

uals

peci

fyre

duce

dsi

gnw

idth

limits

for

incr

ease

dsp

acin

gs.

G2.

Ref

erto

MU

TCD

guid

elin

esfo

rsi

gncl

eara

nces

from

kerb

face

and

shou

lder

edge

and

sign

orie

ntat

ion

toro

ad.A

lso

refe

rto

SD

1365

for

brea

kaw

aypo

stcl

eara

nces

and

Not

eG

8.

G3.

Ref

erto

TC93

82fo

rdi

men

sion

san

dsp

ecifi

catio

nsof

type

1&

2al

umin

ium

pane

lstif

fene

rs.R

efer

tosp

ecifi

catio

nES

126

for

fixin

gsto

sign

face

.

G4.

Sel

ectio

nof

foun

datio

nty

pean

dst

reng

thca

tego

ryto

beap

prov

edby

Pri

ncip

al.

G5.

Opt

iona

lere

ctio

ncl

eats

tobe

prov

ided

onR

HS

post

son

ly,

asre

quire

d.

G6.

Slip

base

and

fuse

plat

ede

tails

and

are

tobe

inco

rpor

ated

inbr

eaka

way

post

son

ly,a

sin

stru

cted

byth

epr

inci

pal.

G7.

Foot

ing

dept

h‘L’

isem

bedm

entl

engt

hin

toso

ilof

stre

ngth

cate

gory

tabu

late

d.D

isre

gard

loos

eto

pso

ilan

dfil

lwhe

nm

easu

ring

foot

ing

dept

h.

G8.

Min

imum

slip

clea

ranc

e‘H

s’fo

rbr

eaka

way

post

sis

2100

mm

.Sig

nhe

ight

‘B’m

ustn

otex

ceed

1.65

x‘H

’for

brea

kaw

aypo

sts

unle

ssot

herw

ise

advi

sed

bypr

inci

pal.

D

1365

E

1365

TRA

FFIC

SIG

NS

UP

PO

RT

TR

AFFIC

SIG

N

Dra

win

gN

o

1363

Dat

e09

/95

Siz

eA

4

DE

Not to

scal

e

Appendix D Design Guide for Roadside Signs


DD

Standard Drawing No. 1364 � Connection Strap and Erection Cleat Details

11m

mdi

a.ho

les

Con

nect

ion

plat

e6m

mga

lv.m

ildst

eel

CH

S/R

HS

CH

S/R

HS

Con

nect

ion

stra

p

Alu

min

ium

Alu

min

ium

10m

mga

lv.s

quar

ene

ckcu

phea

dbo

lts,

incl

.hex

.nut

san

dw

ashe

rs

10m

mga

lv.s

quar

ene

ckcu

phea

dbo

lts,

incl

.hex

.nut

san

dw

ashe

rs

Alu

min

ium

stiff

ener

(see

note

G3

onS

D13

63)

Alu

min

ium

stiff

ener

(see

note

G3

onS

D13

63)

(E48

/W50

)6

5

Sig

nfa

ce Sig

nfa

ce

Col

dga

lvan

ise

wel

dar

eafo

rpr

egal

vani

sed

post

s

Erec

tion

clea

t6m

mga

lv.

mild

stee

l

C L C L

stiff

ener

stiff

ener

CH

S/R

HS

CH

S/R

HS

‘w’

65

50 50

25 25

‘w’/

2 25

RH

Ssm

alle

st

dim

ensi

on

RH

Ssm

alle

st

dim

ensi

on

RH

Sla

rges

t

dim

ensi

on

RH

Sla

rges

t

dim

ensi

on

‘x’

‘t’

*2.

5/3m

mga

lvan

ised

stee

l

G45

0Z2

75

See

Tabl

e2

‘t’

‘r’

‘d’

‘y’

21 3

REA

RELEV

ATIO

N

REA

RELEV

ATIO

N

RH

S

NO

TE:

App

rove

dal

tern

ativ

esi

gnbr

acke

tsca

nbe

used

whe

reap

plic

able

.

CH

S

STIF

FEN

ER

CO

NN

EC

TIO

NS

TR

AP

DETA

ILA

ER

EC

TIO

NC

LEAT

(Opt

iona

l-se

eno

teG

5on

SD

1363)

RH

Spo

sts

only

B

SEC

TIO

N1

SEC

TIO

N3

SEC

TIO

N2

PO

ST

DIM

ENS

ION

S

(mm

)

50N

B

65N

B

80N

B

90N

B

100N

B

125N

B

150N

B

30 38 45 51 57 70 83

‘x’(

mm

)

50 50 75 100

100

25 33 40 46 52 65 78

‘y’(

mm

)

70 95 120

145

195

40 40 40 40 40 50 50

‘w’(

mm

)

40 40 50 50 50

2.5

G45

0Z2

75

2.5

G45

0Z2

75

2.5

G45

0Z2

75

2.5

G45

0Z2

75

2.5

G45

0Z2

75

3.0

G45

0Z2

75

3.0

G45

0Z2

75

‘t’(m

m)

2.5

G45

0Z2

75

2.5

G45

0Z2

75

3.0

G45

0Z2

75

3.0

G45

0Z2

75

3.0

G45

0Z2

75

75x

50

100

x50

125

x75

150

x10

0

200

x10

0

‘r’(

mm

)‘d

’(m

m)

‘t’(m

m)

‘w’(

mm

)

CO

NN

ECTI

ON

STR

AP

S

CH

S

RH

S

TAB

LE

2

CO

NN

ECTI

ON

STR

AP

AN

D

EREC

TIO

NC

LEA

TD

ETA

ILS

TR

AFFIC

SIG

N

Dra

win

gN

o

1364

Dat

e03

/95

Siz

eA

4

B

Not to

scal

e



DD

Standard Drawing No. 1365 � Traffic Sign Support Breakway Post Details (two or more supports)

FU

SE

PLATE

DETA

IL(T

WO

OR

MO

RE

SU

PP

OR

TS

ON

LY)

Ref

erto

Tabl

e3

for

dim

ensi

ons

‘Tf’

,‘m

’,‘S

f’E

TR

AFFIC

SIG

N

TRA

FFIC

SIG

NS

UP

PO

RT

BR

EAK

AW

AY

PO

ST

DET

AIL

S

(TW

OO

RM

OR

ES

UP

PO

RTS

)

Dra

win

gN

o

Dat

e09

/95

1365

Siz

eA

4

CD

Not to

scal

e

‘Tb’

‘Tb’

75

Foot

ing

Post

exte

nds

into

foot

ing

sim

ilar

tost

anda

rdpo

sts

2w

ashe

rsun

der

bolt

head

1w

ashe

rson

top

ofke

eper

plat

e

2w

ashe

rs

4ga

lvan

ised

.gra

de8.

8bo

lts,d

iam

eter

‘p’.

Sup

ply

5w

ashe

rspe

rbo

lt.S

hop

asse

mbl

ed.

Ref

erto

note

B3

for

tight

enin

gto

rque

.

Rem

ove

galv

anis

ing

runs

orbe

ads

atw

ashe

rar

ea

Keep

erpl

ate

see

sect

ion

XN

yloc

nut

X

Y

SLIP

BA

SE

DETA

IL

Ref

erto

Tabl

e3

for

dim

ensi

ons

‘Tb’

,‘S

b’,

‘V’,

‘p’

D

6mm

fille

twel

dfu

llw

idth

ofpl

ate

6mm

fille

twel

dab

ove

cut

Fuse

plat

eto

each

side

Fille

twel

d‘S

f’be

low

cut

Fille

twel

d‘S

f’be

low

cut

Ref

erto

note

B7

Post

cutt

hrou

ghat

fuse

plat

ehi

nge

Sig

nfa

ce

50R

HS

40C

HS

50R

HS

40C

HS

SID

EELEV

ATIO

N(C

HS

/RH

S)

Z

Fille

twel

d‘S

f’be

low

cut

‘m’

Bot

tom

ofsi

gnfa

ce 6

Abo

vecu

t

100

Cut

behi

nd

50R

HS

40C

HS

50R

HS

40C

HS

FR

ON

TELEV

ATIO

N(C

HS

/RH

S)

Tape

red

slot

sfo

rbo

ltsin

uppe

ran

dlo

wer

base

plat

es-

radi

usto

suit

bolt

diam

eter

25

30°

30°

25 20

30

Bol

tdia

.

3535

3535

RH

Sw

idth

CH

Sou

side

diam

eter

(75

min

.spa

cing

)

‘Sb’

‘Sb’

5mm

radi

usto

corn

ers

typ.

Dia

met

er‘V

’ga

lvan

ised

vent

drai

nho

ledi

agon

ally

oppo

site

vent

air

hole

RH

SB

AS

EP

LATE

CH

SB

AS

EP

LATE

X

1.2m

mth

ick

galv

anis

edst

eelk

eepe

rpl

ate

3mm

typ.

Bas

epla

teou

tline

4ho

les,

2mm

over

size

onbo

ltdi

amet

er

KEEP

ER

PLATE

Y

‘m’ ‘T

f’

Abo

vecu

tS

ign

face

6(E

48/W

50)

RH

SS

EC

TIO

NZ

‘m’

‘Tf’

Abo

vecu

tS

ign

face

Fuse

plat

era

dius

tosu

itC

HS

outs

ide

radi

us

6(E

41/W

40) C

HS

SEC

TIO

NZ

PO

ST

SIZ

EP

OS

TS

IZE

WA

LLTH

ICK

NES

SW

ALL

THIC

KN

ESS

65N

B

80N

B

90N

B

100N

B

125N

B

150N

B

65N

B

80N

B

90N

B

100N

B

125N

B

150N

B

3.2

3.2

3.2

3.6

5.0/

3.5

5.0/

3.2

4.0

3.0

5.0

5.0

5.0

3.2

3.2

5.5

3.2

3.2

3.2

3.6

5.0/

3.5

5.0/

3.2

4.0

3.0

5.0

5.0

5.0

3.2

3.2

5.5

C35

0

C35

0

C35

0

C35

0

C25

0/C

350

C25

0/C

350

C45

0

C45

0

C45

0

C35

0

C35

0

C35

0

C35

0

C35

0

C35

0

C35

0

C35

0

C35

0

C25

0/C

350

C25

0/C

350

C45

0

C45

0

C45

0

C35

0

C35

0

C35

0

C35

0

C35

0

16 16 16 16 20 20 20 20 25 25 25 16 16 2016 16 16 16 20 20 20 20 25 25 25 16 16 20

M16

M16

M16

M16

M16

M20

M16

M16

M20

M20

M20

M16

M16

M16

M16

M16

M16

M16

M16

M20

M16

M16

M20

M20

M20

M16

M16

M16

8 8 8 8 8 8 10 8 12 10 108 8 8 8 8 8 10 8 12 10 10

8 8 8 8 8 8 8 8 10 10 108 8 8 8 8 8 8 8 10 10 10

25 25 25 25 32 32 25 32 32 38 5025 25 25 25 32 32 25 32 32 38 50

3 3 3 3 3 3 3 3 4 4 43 3 3 3 3 3 3 3 4 4 4

45 55 60 70 85 100 35 60 60 75 7545 55 60 70 85 100 35 60 60 75 75

100

x50

125

x75

125

x75

150

x10

0

200

x10

0

100

x50

125

x75

125

x75

150

x10

0

200

x10

0

T1(6

5NB

)

T2(8

0N

B)

T3(8

0N

B)

T1(6

5NB

)

T2(8

0N

B)

T3(8

0N

B)

GR

AD

E

‘Tb’

‘Tb’

‘p’

‘p’

‘Sb’

‘Sb’

‘Tf’

‘Tf’

‘V’

‘V’

‘Sf’

‘Sf’

‘m’

‘m’

SLI

PB

AS

ED

ETA

ILS

LIP

BA

SE

DET

AIL

FUS

EP

LAT

ED

ETA

ILFU

SE

PLAT

ED

ETA

IL

MU

LTIP

OLE

SLI

PB

AS

ED

ETA

ILM

ULT

IPO

LES

LIP

BA

SE

DET

AIL

CH

S

RH

S

TRU

SS

TAB

LE

3

BR

EA

KA

WAY

NO

TES

:

B1.

Ref

erto

stee

lnot

esS

1-5

ondr

awin

gN

o.S

D13

66.

B2.

Slip

base

tobe

shop

asse

mbl

edw

ithco

rrec

tbol

tten

sion

ing

prio

rto

tran

spor

tto

site

whe

repo

ssib

le.

B3.

Hig

hst

reng

thga

lvan

ised

bolts

tobe

clea

ned,

light

lyoi

led

and

tens

ione

das

follo

ws:

M36

-10

0Nm

M20

-30

Nm

M16

-20

Nm

.

B4.

Ass

embl

eup

per

tolo

wer

base

plat

ew

ithon

efla

twas

her

onea

chbo

ltbe

twee

npl

ates

with

was

her

abov

eth

eke

eper

plat

e.

B5.

Sea

lgap

betw

een

base

plat

esw

ithca

ulki

ngco

mpo

und.

B6.

Fille

twel

dof

post

toba

sepl

ate

tobe

with

E48X

Xor

W50

XM

IGw

eldi

ng.

B7.

The

post

ends

atth

ecu

tare

tobe

full

cont

acti

nac

cord

ance

with

AS

100

Cl.

14.4

.4.2

requ

irem

ents

for

full

cont

actc

ompr

essi

onsp

lice.

B8.

Wel

dat

fuse

plat

e:

RH

S-

E48X

Xor

W50

XM

IGw

eldi

ng.

CH

S-

E41X

Xor

W40

XM

IGw

eldi

ng.

Wel

dsi

zes

are

tobe

stri

ctly

adhe

red

to,t

oen

sure

satis

fact

ory

perf

orm

ance

offu

sepl

ate

hing

e.

B1.

Ref

erto

stee

lnot

esS

1-5

ondr

awin

gN

o.S

D13

66.

B2.

Slip

base

tobe

shop

asse

mbl

edw

ithco

rrec

tbol

tten

sion

ing

prio

rto

tran

spor

tto

site

whe

repo

ssib

le.

B3.

Hig

hst

reng

thga

lvan

ised

bolts

tobe

clea

ned,

light

lyoi

led

and

tens

ione

das

follo

ws:

M36

-10

0Nm

M20

-30

Nm

M16

-20

Nm

.

B4.

Ass

embl

eup

per

tolo

wer

base

plat

ew

ithon

efla

twas

her

onea

chbo

ltbe

twee

npl

ates

with

was

her

abov

eth

eke

eper

plat

e.

B5.

Sea

lgap

betw

een

base

plat

esw

ithca

ulki

ngco

mpo

und.

B6.

Fille

twel

dof

post

toba

sepl

ate

tobe

with

E48X

Xor

W50

XM

IGw

eldi

ng.

B7.

The

post

ends

atth

ecu

tare

tobe

full

cont

acti

nac

cord

ance

with

AS

100

Cl.

14.4

.4.2

requ

irem

ents

for

full

cont

actc

ompr

essi

onsp

lice.

B8.

Wel

dat

fuse

plat

e:

RH

S-

E48X

Xor

W50

XM

IGw

eldi

ng.

CH

S-

E41X

Xor

W40

XM

IGw

eldi

ng.

Wel

dsi

zes

are

tobe

stri

ctly

adhe

red

to,t

oen

sure

satis

fact

ory

perf

orm

ance

offu

sepl

ate

hing

e.



DD

Standard Drawing No. 1366 � Traffic Sign Support Detail � Truss Type Breakway

Bre

adth

(B)

Wid

th(W

)

PLA

N

Sig

nfa

ceEx

tern

alfit

ted

plug

.R

efer

note

S6

75

Ove

rhan

gva

ries

tosu

itsp

ecifi

edpo

stle

ngth

(max

1.75

Sm

in15

0m

m)

Pin

diam

eter

Signheight‘B’

(seenoteG7)

Clearance‘H’

(seenotesG6&G7)

Postlengthasspecified

(breakawayandnon-breakaway)

150

150

100

min

.

100

max

.

Dep

th(D

)

SID

EELEV

ATIO

N

300m

mm

ax.

150mm

Hor

izon

tal

web

stru

t

*A

djus

tthe

over

hang

toav

oid

havi

nga

fuse

plat

ew

ithin

50m

mof

aw

ebno

de.

Hor

izon

talw

ebst

ruts

200

from

top

and

botto

mof

stub

s.

StubLength(st)

ReferTable

Fuse

plat

e.R

efer

deta

ilon

SD

1367

2.1mmin.

slipclearance‘Hs’

*

Leve

loft

opst

rut.

Ref

erno

teG

4

Bot

tom

stru

tabo

vebo

ttom

ofsi

gnfa

ce.

Ref

erno

teG

4

Pitc

h=2

xS

Post

spac

ing

(S)

Dia

gona

lbra

ces

toun

supp

orte

dle

g.R

efer

note

G4

Top

com

pres

sive

leg

stru

tsys

tem

.R

efer

note

G4

Bot

tom

com

pres

sive

leg

stru

tsys

tem

Slip

base

.R

efer

SD

1365

100

max

.

Stu

bsem

bedd

edin

toco

ncre

tefo

otin

g75

cove

rm

in.

REA

RELEV

ATIO

N

Slo

peco

ncre

tesu

rfac

eaw

ayfro

mpo

stat

1:6

Bra

cing

chor

dan

dad

apto

rsto

beus

edto

alig

nst

ubs

prio

rto

conc

retre

setti

ng.

Ref

erN

ote

G4

Trus

ssp

acin

g2

Trus

ses:

0.6

xS

ign

Wid

th3

Trus

ses:

0.35

xS

ign

Wid

th4

Trus

ses:

0.25

xS

ign

Wid

th

Fuse

plat

e.R

efer

deta

ilon

SD

1367

Sig

nat

tach

men

t.S

eede

tail

onS

D13

64

Roa

dsi

de

<25

00ty

peA

trus

ses

(S=

750)

>25

00<

3250

type

Btr

usse

s(S

=10

00)

Imm

edia

tele

gst

rut

at3m

CTS

max

.(i

freq

uire

d)

S

TRA

FFIC

SIG

NS

UP

PO

RTD

ETA

IL

TRU

SS

TYP

EB

REA

KA

WA

Y

GEN

ER

AL

NO

TES

:

CO

NC

RETE

NO

TES

:

BR

EA

KA

WAY

NO

TES

:

G1.

Sta

ndar

dpo

stsp

acin

gis

nott

obe

alte

red

with

outa

ppro

valo

fpri

ncip

al.

G2.

Ref

erto

TC93

82fo

rdi

men

sion

san

dsp

ecifi

catio

nsof

type

1&

2al

umin

ium

pane

lst

iffen

ers.

Ref

erto

spec

ifica

tion

ES12

6fo

rfix

ings

tosi

gnfa

ce.

G3.

Ref

erto

SD

1364

for

deta

ilsof

conn

ecto

rst

raps

.

G4.

Ref

erto

SD

1367

for

deta

ilsof

unsu

ppor

ted

leg

stru

tsys

tem

and

adap

tor

plat

e.

G5.

For

non-

slip

base

supp

orts

excl

ude

keep

erpl

ate

and

fuse

plat

ede

tails

.Bas

eA

ssem

bly

still

requ

ired

unle

sssp

ecifi

edas

notb

eing

requ

ired

bypr

inci

ple.

G6.

Ref

erto

MU

TCD

guid

elin

esfo

rsi

gncl

eara

nces

from

kerb

face

and

shou

lder

edge

and

sign

orie

ntat

ion

toro

ad.A

lso

refe

rto

SD

1365

for

brea

kaw

aypo

stde

tails

.

G7.

Min

imum

slip

clea

ranc

e‘H

s’fo

rbr

eaka

way

post

sis

2100

mm

.Sig

nhe

ight

‘B’m

ustn

otex

ceed

1.65

x‘H

’for

brea

kaw

aypo

sts

unle

ssot

herw

ise

advi

sed

bypr

inci

pal.

G1.

Sta

ndar

dpo

stsp

acin

gis

nott

obe

alte

red

with

outa

ppro

valo

fpri

ncip

al.

G2.

Ref

erto

TC93

82fo

rdi

men

sion

san

dsp

ecifi

catio

nsof

type

1&

2al

umin

ium

pane

lst

iffen

ers.

Ref

erto

spec

ifica

tion

ES12

6fo

rfix

ings

tosi

gnfa

ce.

G3.

Ref

erto

SD

1364

for

deta

ilsof

conn

ecto

rst

raps

.

G4.

Ref

erto

SD

1367

for

deta

ilsof

unsu

ppor

ted

leg

stru

tsys

tem

and

adap

tor

plat

e.

G5.

For

non-

slip

base

supp

orts

excl

ude

keep

erpl

ate

and

fuse

plat

ede

tails

.Bas

eA

ssem

bly

still

requ

ired

unle

sssp

ecifi

edas

notb

eing

requ

ired

bypr

inci

ple.

G6.

Ref

erto

MU

TCD

guid

elin

esfo

rsi

gncl

eara

nces

from

kerb

face

and

shou

lder

edge

and

sign

orie

ntat

ion

toro

ad.A

lso

refe

rto

SD

1365

for

brea

kaw

aypo

stde

tails

.

G7.

Min

imum

slip

clea

ranc

e‘H

s’fo

rbr

eaka

way

post

sis

2100

mm

.Sig

nhe

ight

‘B’m

ustn

otex

ceed

1.65

x‘H

’for

brea

kaw

aypo

sts

unle

ssot

herw

ise

advi

sed

bypr

inci

pal.

C1.

Con

cret

esp

ecifi

catio

n:S

lum

p80

mm

Max

.agg

rega

te20

mm

Min

.cem

entc

onte

nt25

0kg/

mM

ax.w

ater

/cem

entr

atio

0.55

Con

cret

eN

25to

AS

3600

C2.

Mec

hani

cally

vibr

ate

full

dept

hof

conc

rete

.

C3.

Con

cret

epo

ured

dire

ctly

agai

nste

xcav

ated

hole

unle

ssap

prov

edot

herw

ise.

3

C1.

Con

cret

esp

ecifi

catio

n:S

lum

p80

mm

Max

.agg

rega

te20

mm

Min

.cem

entc

onte

nt25

0kg/

mM

ax.w

ater

/cem

entr

atio

0.55

Con

cret

eN

25to

AS

3600

C2.

Mec

hani

cally

vibr

ate

full

dept

hof

conc

rete

.

C3.

Con

cret

epo

ured

dire

ctly

agai

nste

xcav

ated

hole

unle

ssap

prov

edot

herw

ise.

3

B1.

Slip

base

bolts

are

tobe

clea

ned,

light

lyoi

led

and

tens

ione

das

follo

ws:

M36

-10

0Nm

M20

-30

Nm

M16

-20

Nm

.

B2.

Ass

embl

eup

per

tolo

wer

base

plat

ew

ithon

efla

tw

ashe

ron

each

bolt

betw

een

plat

esw

ithw

ashe

rab

ove

the

keep

erpl

ate.

B3.

Sea

lgap

betw

een

base

plat

esw

ithca

ulki

ngco

mpo

und.

B4.

The

post

ends

atth

ecu

tare

tobe

full

cont

acti

nac

cord

ance

with

AS

100

Cl.

14.4

.4.2

requ

irem

ents

for

full

cont

actc

ompr

essi

onsp

lice.

B1.

Slip

base

bolts

are

tobe

clea

ned,

light

lyoi

led

and

tens

ione

das

follo

ws:

M36

-10

0Nm

M20

-30

Nm

M16

-20

Nm

.

B2.

Ass

embl

eup

per

tolo

wer

base

plat

ew

ithon

efla

tw

ashe

ron

each

bolt

betw

een

plat

esw

ithw

ashe

rab

ove

the

keep

erpl

ate.

B3.

Sea

lgap

betw

een

base

plat

esw

ithca

ulki

ngco

mpo

und.

B4.

The

post

ends

atth

ecu

tare

tobe

full

cont

acti

nac

cord

ance

with

AS

100

Cl.

14.4

.4.2

requ

irem

ents

for

full

cont

actc

ompr

essi

onsp

lice.

STEEL

NO

TES

:S

1.S

teel

grad

es(F

Y)to

be:

Sec

tion

and

plat

esto

AS

1204

-25

0Mpa

.

CH

Sto

AS

1163

-25

0/35

0/45

0M

pa,a

ssp

ecifi

ed.

S2.

Wel

ded

conn

ectio

nssh

allb

ew

ith6m

mco

ntin

uous

fille

twel

ds

inac

cord

ance

with

AS

1554

cate

gory

spec

ialp

urpo

se(S

P),

usin

gel

ectr

ode

type

E48X

X/W

50X

MIG

wel

ding

,

exce

ptat

fuse

plat

ew

here

E41X

X/W

40X

elec

trode

sar

eto

beus

ed.

S3.

All

bolts

are

tobe

galv

anis

edgr

ade

8.8

unle

ssno

ted

othe

rwis

e.

S4.

All

bolts

,fitm

ents

,pla

tes,

etc.

tobe

hotd

ippe

dga

lvan

ised

,U.N

.O.

S5.

Cor

rosi

onpr

otec

tion.

CH

Spo

stas

sem

bly

tobe

hotd

ippe

dga

lvan

ised

300g

/m²

afte

rfa

bric

atio

nof

fuse

plat

ean

dsl

ipba

sepl

ates

.

S6.

Exte

rnal

end

plug

sar

eno

tto

befit

ted

prio

rto

galv

anis

ing.

S1.

Ste

elgr

ades

(FY)

tobe

:

Sec

tion

and

plat

esto

AS

1204

-25

0Mpa

.

CH

Sto

AS

1163

-25

0/35

0/45

0M

pa,a

ssp

ecifi

ed.

S2.

Wel

ded

conn

ectio

nssh

allb

ew

ith6m

mco

ntin

uous

fille

twel

ds

inac

cord

ance

with

AS

1554

cate

gory

spec

ialp

urpo

se(S

P),

usin

gel

ectr

ode

type

E48X

X/W

50X

MIG

wel

ding

,

exce

ptat

fuse

plat

ew

here

E41X

X/W

40X

elec

trode

sar

eto

beus

ed.

S3.

All

bolts

are

tobe

galv

anis

edgr

ade

8.8

unle

ssno

ted

othe

rwis

e.

S4.

All

bolts

,fitm

ents

,pla

tes,

etc.

tobe

hotd

ippe

dga

lvan

ised

,U.N

.O.

S5.

Cor

rosi

onpr

otec

tion.

CH

Spo

stas

sem

bly

tobe

hotd

ippe

dga

lvan

ised

300g

/m²

afte

rfa

bric

atio

nof

fuse

plat

ean

dsl

ipba

sepl

ates

.

S6.

Exte

rnal

end

plug

sar

eno

tto

befit

ted

prio

rto

galv

anis

ing.

TAB

LE

5

DIM

ENS

ION

HO

RIZ

ON

TAL

STR

UTS

DIA

GO

NA

LS

TRU

TS

DIA

GO

NA

LB

RA

CES

32N

B

32N

B

40N

B

4.0

4.0

4.0

C250

C250

C250

WA

LLTH

ICK

NES

SG

RA

DE

TAB

LE

4

Trus

sTy

pe

Pos

tS

paci

ngS

(mm

)

Pos

tD

im.

(mm

)

Web

Dim

.(m

m)

Wal

lTh

ickn

ess

(mm

)

Wal

lTh

ickn

ess

(mm

)

Pin

Dia

.(m

m)

Bas

eP

late

Tb(m

m)

Wel

dLe

ngth

n(m

m)

Wel

dLe

ngth

m(m

m)

Wid

thW

(mm

)W

idth

W(m

m)

Bre

adth

B(m

m)

Bre

adth

B(m

m)

Dep

thD

(mm

)D

epth

D(m

m)

Stu

bLe

ngth

st(m

m)

Stu

bLe

ngth

st(m

m)

Bol

tS

ize

pG

rade

Gra

de

TRU

SS

SP

ECIF

ICAT

ION

FOO

TIN

GS

SLI

PB

AS

ED

ETA

IL(s

eeS

D1365)

FUS

EP

LAT

ED

ETA

IL*

(see

SD

1367)

PO

ST

INC

LAY

INS

AN

DW

EB

T1A

T1B

T2A

T2B

T3A

T3B

750

1000 750

1000 750

1000

65N

B

65N

B

80N

B

80N

B

80N

B

80N

B

3.2

3.2

3.2

3.2

5.5

5.5

3.2

3.2

4.0

4.0

4.0

4.0

C35

0

C35

0

C35

0

C35

0

C35

0

C35

0

C25

0

C25

0

C25

0

C25

0

C25

0

C25

0

120

120

120

120

190

190

16 16 16 16 20 20

40 40 45 45 80 80

45 45 55 55 55 55

500

500

500

500

500

500

500

500

500

500

500

500

1200

1500

1200

1500

1200

1500

1200

1500

1200

1500

1200

1500

1300

1300

1600

1600

2000

2000

1600

1600

1900

1900

2000

2000

1600

1600

1900

1900

2000

2000

1300

1300

1600

1600

2000

2000

M16

M16

M16

M16

M16

M16

25N

B

25N

B

25N

B

25N

B

32N

B

32N

B

*Fu

sepl

ate

loca

tion

and

deta

ilsdi

ffer

from

stan

dard

slip

base

supp

ortd

etai

lson

SD

1365

.

TR

AFFIC

SIG

N

Dra

win

gN

o

Dat

e09

/95

1366

Siz

eA

4

EF

Not to

scal

e



DD

Standard Drawing No. 1367 � Traffic Sign Support Detail � Truss Type Breakway Bracing Details

BR

AC

ING

DETA

IL

TRA

FFIC

SIG

NS

UP

PO

RTD

ETA

IL

TRU

SS

TYP

EB

REA

KA

WA

Y

BR

AC

ING

DET

AIL

S

SID

EELEV

ATIO

N150

from

top

ofre

arpo

st

Sig

n

150

from

botto

mof

sign

Trus

sTr

uss

CH

Sen

dsfla

ttene

dC

leat

wel

ded

topo

st

1xM

12bo

lt1x

M12

bolt

Add

ition

alcl

eats

whe

rem

ore

than

two

trus

ses

32N

B

Flat

ten

ends

until

ther

eis

nocl

ash

betw

een

top

&bo

ttom

CH

S

1xM

12bo

lt

Cle

atfo

rdi

agon

albr

ace

(dia

gona

lbra

ceno

tsh

own

for

clar

ity)

Pla

neof

diag

onal

brac

ing

Roa

dsi

de

PLA

N

REA

RELEV

ATIO

N

3mC

TSm

ax.

All

hori

zont

alst

ruts

:32

NB

CH

SA

lldi

agon

albr

aces

:40

NB

CH

S

Str

uts

Str

uts

Str

uts

Diag

onal

brac

e

Diag

onal

brac

e

Diag

onal

brac

e

Diag

onal

brac

e

Str

ut

Str

ut

Str

utX X X

40N

BC

HS

diag

onal

brac

e

ELEV

ATIO

N

Trus

sre

arpo

st

50

125

25

75x7

5x8

PLcl

eat

60w

ide

8m

mPL

clea

t

M12

Bol

t

32N

BC

HS

diag

onal

stru

t

32N

BC

HS

hori

zont

alst

rut

(to

rear

post

son

trus

ses)

FU

SE

PLATE

DETA

IL

*R

efer

toTa

ble

4,S

D13

66fo

rdi

men

sion

s‘m

’and

‘n’.

Z

ELEV

ATIO

N

Cut

50m

in.

Abo

vecu

t

Bel

owcu

t

(E41

/W40

)

(E41

/W40

)

6 4

n* n*

SEC

TIO

N

Abo

vecu

t

Bel

owcu

t

(E41

/W40

)

(E41

/W40

)Tr

uss

axis

Signface

axis

6 4

m*

Z

SP

REA

DER

PLATE

ELEV

ATIO

NS

IDE

ELEV

ATIO

N

Use

dei

ther

side

ofa

post

whe

rea

node

inte

rfer

esw

ithth

elo

catio

nof

ast

iffen

eran

dat

tach

men

tofc

onne

ctor

stra

ps.

Use

norm

albo

ltto

atta

chto

stiff

ener

.

12

90 Gal

vani

sed

mild

stee

l

R4

R4

640

2020

180

140

8050

11di

a.

11di

a.

11di

a.

US

EO

FA

DA

PTO

RP

LATE

AN

DR

OD

FO

RLO

CATIO

NO

FFO

OTIN

GS

Traf

ficsi

gnpo

st

Ada

ptor

rod

Ada

ptor

plat

eLeve

l

BR

AC

ING

INS

TALLATIO

ND

IAG

RA

M

PLA

NX

Hor

izon

tals

trut

Dia

gona

lstru

t

Bra

cing

sets

atto

p,bo

ttom

and

3mC

TSm

ax.i

freq

uire

d

Roa

d

side

FOR

3P

OS

TS

AD

AP

TO

RP

LATE

AN

DR

OD

DETA

IL

M12

nuta

ndLS

was

her

400

M12

nuta

ndLS

was

her

Vert

ical

adap

tor

rod

for

posi

tioni

ngth

ebr

acin

gch

ord

mem

ber

onve

rtic

ally

disp

lace

dfo

otin

gs(2

requ

ired

per

bay)

12di

a.th

read

edro

d

Ada

ptor

piec

eto

allo

wbr

acin

gch

ord

mem

bers

tobe

used

toal

ign

stub

sfo

rfo

otin

gs(4

requ

ired

per

bay)

14di

a.ho

le

20ra

dius

2020

40

125

18di

a.ho

le

5PL

TR

AFFIC

SIG

N

Dra

win

gN

o

1367

Dat

e05

/95

Siz

eA

4

D

Not to

scal

e



DD

Standard Drawing No. 1368 � Single Traffic Sign Support

75m

m75

mm

75m

mco

ver

Leng

thof

post

tobe

orde

red

Leng

thof

post

tobe

orde

red

Leng

thof

stub

Not

e:Fu

sepl

ate

deta

ilis

notu

sed

onsi

ngle

post

sign

s

Alu

min

ium

pane

lst

iffen

ers

Alu

min

ium

pane

lst

iffen

ers

App

rove

dga

lvan

ised

caps

for

post

sA

ppro

ved

galv

anis

edca

psfo

rpo

sts

Post

may

need

tobe

defo

rmed

atba

seto

prev

entr

otat

ion

50N

BC

HS

post

M8

x90

long

high

tens

ilega

lvbo

lt

50

Post

embe

ded

into

conc

rete

65N

BC

HS

galv

slee

ve

50N

BC

HS

post

Dre

ss-r

ing

Loc-

sock

etem

bede

din

toco

ncre

te

Loc-

sock

et

Cle

aran

ce‘H

’*C

lear

ance

‘H’*

‘d’*

‘d’*

‘L’*

‘L’*

*R

efer

toS

D13

63,T

able

1fo

rfo

otin

gan

dty

pica

ldet

ails

1800

max

.18

00m

ax.

SLIP

BA

SE

OR

AS

SEM

BLED

PO

ST

LOW

RIS

KO

RFR

AN

GIB

LE

SU

PP

OR

T

SIN

GLE

PO

ST

SIG

N LOC

-SO

CK

ET

OR

SIM

ILA

RS

YS

TEM

-50N

BP

OS

TS

TY

PIC

AL

SLEEV

EIN

STA

LLATIO

NFO

R50N

BP

OS

TS

TY

PIC

AL

SIN

GLE

PO

ST

CO

NN

EC

TIO

NS

TR

AP

DETA

IL

M10

galv

.squ

are

neck

cuph

ead

bolts

,inc

l.he

x.nu

tsan

dw

ashe

rs

Sig

nfa

ce

Con

nect

ion

stra

p.S

eeS

D13

64fo

rde

tails

20m

mlo

ng,M

10ga

lvan

ised

bolt

Str

apta

pped

for

M10

bolt

12m

mdi

a.ho

ledr

illed

onsi

te

5

Alu

min

ium

stiff

ener

PO

ST

DIM

ENS

ION

S(m

m)

SLI

PB

AS

ETH

ICK

NES

S‘T

b’(m

m)

BO

LTD

IAM

ETER

‘p’

RA

DIU

S‘r

’(m

m)

CH

S

RH

S

SIN

GLE

PO

LES

LIP

BA

SE

DET

AIL

50N

B

65N

B

80N

B

90N

B

100N

B

125N

B

150N

B

100

x50

x4

125

x75

x3

125

x75

x5

16 20 20 32 32 32 32 32 32 32

M16

M16

M16

M20

M20

M24

M24

M20

M24

M24

65 70 75 80 100

100

115 85 100

115

For

Slip

Bas

eno

tese

eS

D13

65.

For

Gen

eral

Ste

el&

Con

cret

eno

tes

see

SD

1363

.

SEC

TIO

N2

SIN

GLE

TRA

FFIC

SIG

NS

UP

PO

RT

TR

AFFIC

SIG

N

Dra

win

gN

o

1368

Dat

e02

/200

1

Siz

eA

4

AB

Not to

scal

eC

50N

BC

HS

post

Met

alw

edge

driv

enin

toso

il

TY

PIC

AL

WED

GE

INS

TALLATIO

NFO

R50

NB

PO

STS

*R

efer

tom

anuf

actu

rer’

ssp

ecifi

catio

nfo

rgu

idan

ceon

inse

rtio

nde

pth

and

conn

ectio

nde

tails

.

L*

CH

S/R

HS

SIN

GLE

PO

ST

SLIP

BA

SE

‘Sb’

refe

r‘C

HS

/RH

S’

base

plat

esi

mila

r

‘v’

RH

Spo

stsi

mila

r

‘r’

5ra

dius

Cor

ners

seto

uton

circ

ular

arc

Bol

ts,d

iam

eter

‘p’

Sig

nfa

ce

30° 120°

30°

30

SLIP

BA

SE

DETA

ILR

efer

SD

13

65

D(

)

1.2m

mth

ick

galv

anis

edst

eelk

eepe

rpl

ate

10



DD

Standard Drawing No. 1450 � Traffic Sign Support Timber Posts

Alu

min

ium

pane

lstif

fene

rs(s

eeno

teG

3)

Post

top

tape

r1:

6

Type

2al

umin

ium

pane

lst

iffen

ers

Saw

nor

roun

dtim

ber

post

s(r

efer

Tabl

e1

for

deta

ils)

Post

embe

dded

into

conc

rete

foot

ings

150

max

.ov

erha

ng

500

max

.st

iffen

ersp

acin

g 100

max

.ov

erha

ng

Saw

ntim

ber

smal

lest

dim

ensi

on

Saw

ntim

ber

larg

est

dim

ensi

on

Gro

und

leve

latf

ootin

gto

beco

nfir

med

prio

rto

fabr

icat

ion

ofpo

sts

Ref

erto

Tabl

e1

for

foot

ing

and

typi

cald

etai

ls

Bre

akaw

ayba

se

Typi

cal

1800

max

.

Bre

akaw

ayba

se

See

SD

1451

Sig

nhe

ight

‘B’

Cle

aran

ce‘H

’(s

eeno

tes

G2

&G

6)

‘L’(s

eeno

teG

5)

‘d’

‘d’

‘L’

Slo

peco

ncre

tesu

rfac

eaw

ayfro

mpo

stat

1:6

B/C 69

B/C 69

A 69

A 69

D 69

Sta

ndar

dpo

stsp

acin

g(s

eeno

teG

1)0.

60x

sign

wid

thfo

r2

post

s0.

35x

sign

wid

thfo

r3

post

s0.

25x

sign

wid

thfo

r4

post

s

PO

ST

DIM

ENS

ION

S(m

m)

125

ø

150

ø

175

ø

200

ø

150

x75

175

x75

200

x10

0

GR

AD

E

F14

F14

F14

F14

F8 F8 F8 F14

F14

F14

F14

d(m

m)

300

300

450

450

300

450

450

450

450

450

450

L(m

m)

700

900

900

1200

900

800

1200

900

1050

1200

1350

d(m

m)

300

300

450

450

300

300

450

450

450

450

450

L(m

m)

600

750

750

900

750

800

900

750

800

900

1100

d(m

m)

300

300

450

450

300

300

450

450

450

450

450

L(m

m)

1000

1100

1200

1350

1100

1200

1350

1200

1300

1350

1600

d(m

m)

300

300

300

450

300

300

450

300

450

450

450

L(m

m)

800

900

1200

1200

900

1000

1200

1200

1200

1200

1300

FIR

MTO

STI

FFV

ERY

STI

FF

CO

HES

IVE

CLAY

SO

ILS

LOO

SE

TOM

EDIU

MD

ENS

E

CO

HES

ION

LES

SS

AN

DS

OIL

S

RO

UN

DS

FOO

TIN

GS

(SEE

NO

TEG

4)

PO

ST

SP

ECIF

ICAT

ION

SA

WN

HA

RD

WO

OD

1200

300

1200

450

750

450

900

450

F820

0x

75

200

x75

200

x10

0

175

x75

150

x75

150

x75

200

x75

200

x10

0F5

450

750

450

750

450

900

450

750

750

800

450

300

900

1000

450

300

600

600

450

300

750

700

450

300

F5F5

PIN

E

SA

WN

FR

ON

TELEV

ATIO

N

FR

ON

TELEV

ATIO

N

SID

EELEV

ATIO

N

GEN

ER

AL

NO

TES

:

TIM

BER

NO

TES

:

G1.

Sta

ndar

dpo

stsp

acin

gm

ustn

otto

beal

tere

dw

ithou

tapp

rova

lofp

rinc

ipal

.Tab

les

inth

eR

oad

Sig

nD

esig

nM

anua

lspe

cifiy

redu

ced

sign

wid

thlim

itsfo

rin

crea

sed

spac

ing

of2

post

supp

orts

.

G2.

Ref

erto

MU

TCD

guid

elin

esfo

rsi

gncl

eara

nces

from

kerb

face

and

shou

lder

edge

and

sign

orie

ntat

ion

toro

ad.A

lso

refe

rto

note

G6

for

brea

kaw

aypo

sts.

G3.

Ref

erto

TC93

82fo

rdi

men

sion

san

dsp

ecifi

catio

nsof

type

1&

2al

umin

ium

pane

lst

iffen

ers.

Ref

erto

spec

ifica

tion

ES12

6fo

rfix

ings

tosi

gnfa

ce.

G4.

Sel

ectio

nof

foun

datio

nty

pean

dst

reng

thca

tego

ryto

beap

prov

edby

prin

cipa

l.

G5.

Foot

ing

dept

h‘L’

isem

bedm

entl

engt

hin

toso

ilof

stre

ngth

cate

gory

tabu

late

d.D

isre

gard

loos

eto

pso

ilan

dfil

lwhe

nm

easu

ring

foot

ing

dept

h.

G6.

Min

imum

clea

ranc

e‘H

’for

brea

kaw

aypo

sts

is21

00m

m.

T1.

Dur

abili

tyan

dpr

eser

vativ

etre

atm

ent

(i)

Pla

ntat

ion

softw

ood

post

s,ro

und

orsa

wn,

shal

lbe

pres

erva

tive

treat

edin

acco

rdan

cew

ithA

S16

04to

‘H4’

leve

l.S

awn

timbe

rsh

allh

ave

am

axim

umof

20%

ofun

treat

edhe

artw

ood.

(ii)

Har

dwoo

dpo

sts

shal

lbe

dura

bilit

ycl

ass

1or

2an

dsh

allh

ave

any

sapw

ood

pres

ent

pres

erva

tive

treat

edin

acco

rdan

cew

ithA

S16

04to

‘H4’

leve

l.

T2.

Stre

ngth

(i)

Rou

ndpl

anta

tion

softw

ood

post

ssh

allb

em

inim

umst

reng

thgr

oup

S5.

(ii)

Saw

npl

anta

tion

softw

ood

post

ssh

allb

em

inim

umst

ress

grad

eF5

inac

cord

ance

with

the

rele

vant

Aus

tral

ian

stan

dard

for

visu

al,

mac

hine

orpr

oofg

radi

ng.

(iii)

Saw

nha

rdw

ood

post

ssh

allb

ea

min

imum

stre

ssgr

ade

ofF8

/F14

asno

ted

onTa

ble

1.

T3.

Tole

ranc

es

(i)

Rou

ndpl

anta

tion

softw

ood

post

ssh

allb

em

achi

ned

roun

dan

dsh

allb

e-0

,+4m

mof

nom

inal

diam

eter

.

(ii)

Saw

ntim

ber

post

ssh

allb

e±

3mm

ofno

min

aldi

men

sion

s.

(iii)

All

post

ssh

allh

ave

am

axim

umsp

ring

orbo

wof

12m

min

2.4m

oreq

uiva

lent

.

T4.

Moi

stur

eco

nten

t

Uns

easo

ned

timbe

rpo

sts

shal

lhav

eth

eir

end

grai

nse

aled

and

plat

edto

min

imis

esp

littin

gan

dsh

rink

ing

crac

ks.

TAB

LE

1

SIN

GLE

PO

ST

SIG

N

CO

NC

RETE

NO

TES

:

C1.

Con

cret

esp

ecifi

catio

n:

Slu

mp

80m

mM

ax.a

ggre

gate

20m

mC

oncr

ete

N25

toA

S36

00

C2.

Mec

hani

cally

vibr

ate

full

dept

hof

conc

rete

.

C3.

Con

cret

epo

ured

dire

ctly

agai

nste

xcav

ated

hole

unle

ssap

prov

edot

herw

ise.

TRA

FFIC

SIG

NS

UP

PO

RT

TIM

BER

PO

STS

TR

AFFIC

SIG

N

Dra

win

gN

o

Dat

e09

/95

1450

Siz

eA

4

AB

Not to

scal

e



DD

Standard Drawing No. 1451 � Timber Support Details

Sig

nfa

ceor

ient

atio

nS

ign

face

orie

ntat

ion

50x

3G

450

Z275

galv

anis

edst

eelb

rack

ets

2-

No.

14ty

pe17

hex

head

galv

scre

ws

(50

long

)to

each

brac

ket.

Bra

cket

spr

edr

illed

.

No.

14ty

pe17

hex

head

galv

scre

ws

(50

long

)th

rupr

edr

illed

stra

p(6

mm

hole

)

55

‘t’

‘r’

‘w’

‘v’

50

ø6ho

leø1

1ho

le

Alu

min

ium

stiff

ener

sA

lum

iniu

mst

iffen

ers

M10

galv

.squ

are

neck

cuph

ead

bolt,

incl

.hex

.nut

san

dw

ashe

rs

M10

galv

.squ

are

neck

cuph

ead

bolt,

incl

.hex

.nut

san

dw

ashe

rs

M10

galv

.coa

chbo

lt50

embe

dmen

t

Typi

cal5

0x3

conn

ectio

nst

raps

tobo

thsi

des

ofpo

st

Pre

drill

ed6m

mho

le

Con

nect

ion

stra

pre

fer

M10

bolt

and

stiff

ener

-re

fer

Sta

ndar

ddw

g.N

o.13

64

M10

bolt

and

stiff

ener

-re

fer

Sta

ndar

ddw

g.N

o.13

64

Z275

galv

anis

edst

eels

trap

Bra

cket

both

side

sfo

r17

5&

200

deep

hard

woo

dpo

sts

only

Cen

tral

core

diam

eter

,Dc

Hol

esth

roug

hfo

rco

ncre

tefil

ling

ofco

re,

Dia

met

erD

h@

300

crs

Keyh

ole

diam

eter

,Dk

Slo

t

A

A

B

5

400

50

50 50 25

75

Dc

Dk

Con

cret

efo

otin

g

RO

UN

DTIM

BER

SA

WN

TIM

BER

BR

EA

KA

WAY

BA

SE

SIN

GLE

PO

ST

CO

NN

EC

TIO

N

SIN

GLE

PO

ST

CO

NN

EC

TIO

N

STR

AP

DETA

IL-

SA

WN

STR

AP

DETA

IL-

RO

UN

DS

A

STIF

FEN

ER

CO

NN

EC

TIO

N

STR

AP

DETA

IL-

SA

WN

B

STIF

FEN

ER

CO

NN

EC

TIO

N

STR

AP

DETA

IL-

RO

UN

DS

A

D

D

SA

WN

PIN

E

F5 F5

- -

- -

- 75

- -

1 1 1-

75-

-F5

F8/F

14-

-75

-2

HA

RD

WO

OD

SA

WN

RO

UN

DS

CO

NN

ECTI

ON

STR

AP

BR

EAK

AW

AYB

AS

E

221----

No.

PER

PO

ST

---

100

887563‘r’

‘w’

‘v’

‘t’

755025----

Dk(

mm

)

---757550-

Dh(

mm

)

---

125

100

75-

Dc(

mm

)

F8/F

14

F8/F

14

F8/F

14

F14

F14

F14

F14

GR

AD

E

SIZ

E(m

m)

PO

ST

RO

UN

DS

SA

WN

60 72 85 97 - - -- ---

40 40 40 50 - - -- ---

2.5

2.5

2.5

3.0 - - -- ---

125

ø

150

ø

175

ø

200

ø

150

x75

175

x75

200

x10

0

200

x75

200

x75

200

x10

0

150

x75

TAB

LE

2

SEC

TIO

NA

SEC

TIO

NB

TIM

BER

SU

PP

ORT

DET

AIL

S

TR

AFFIC

SIG

N

Dra

win

gN

o

Dat

e09

/95

1451

Siz

eA

4

CD

Not to

scal

e



DD

des guide 1 roadside signs

Documents