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volume 5 ASSeSSmeNT AND PRePARATIoN oF RoAD SCHemeS SeCTIoN 1 ASSeSSmeNT oF RoAD SCHemeS

PART 4

TA 11/09

TRAFFIC SuRveYS BY RoADSIDe INTeRvIeW

SummARY

Having reliable information about existing journeys is vital to help inform future transport strategies. This document provides advice on the procedures and techniques for obtaining this information safely from drivers through face-to-face interviews at the roadside.

INSTRuCTIoNS FoR uSe

This Advice Note includes advice on the layout of roadside interview sites and it should read in conjunction with Chapter 8 of the Traffic Signs Manual.

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DeSIGN mANuAl FoR RoADS AND BRIDGeS

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DeSIGN mANuAl FoR RoADS AND BRIDGeS TA 11/09 volume 5, Section 1, Part 4

THe HIGHWAYS AGeNCY

TRANSPoRT SCoTlAND

WelSH ASSemBlY GoveRNmeNT llYWoDRAeTH CYNullIAD CYmRu

THe DePARTmeNT FoR ReGIoNAl DeveloPmeNT NoRTHeRN IRelAND

Traffic Surveys by Roadside Interview

Summary: Havingreliableinformationaboutexistingjourneysisvitaltohelpinformfuture transportstrategies.Thisdocumentprovidesadviceontheproceduresand techniquesforobtainingthisinformationsafelyfromdriversthroughface-to-face interviewsattheroadside.

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volume 5 Section 1 Part 4 TA 11/09

ReGISTRATIoN oF AmeNDmeNTS

Amend No

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volume 5 ASSeSSmeNT AND PRePARATIoN oF RoAD SCHemeS SeCTIoN 1 ASSeSSmeNT oF RoAD SCHemeS

PART 4

TA 11/09

TRAFFIC SuRveYS BY RoADSIDe INTeRvIeW

Contents

Chapter

1. Introduction

2. Survey Planning

3. Interview Site Locations and Layouts

4. Staffing and Site Operation

5. Contingency Planning

6. Alternative Survey Methods

7. Sampling and Address Coding

8. References

9. Enquiries

Annexes

Annex 1 Definitions used in Roadside Interview Surveys

Annex 2 Legal Framework for England

Annex 3 Example Press Release

Annex 4 Signing Principles and Typical Site Layouts

Annex 5 Example Traffic Count and Interview Forms

Annex 6 Example leaflet

Annex 7 Managing Congestion

Annex 8 Sampling

DeSIGN mANuAl FoR RoADS AND BRIDGeS

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Chapter 1 Introduction

1. INTRoDuCTIoN

General

1.1 Decisions about future transport strategy rely upon good information about the journeys currently being made by travellers. The roadside interview (RSI) process is disruptive and has inherent, manageable risks. Safety to the staff involved and the general travelling public can be mitigated and data integrity improved by following the advice in this document. Thorough planning of work is essential for success. Those commissioning studies involving RSI should always consider very carefully the value of the data and alternative methods of collection first. However, for drivers this information is usually best obtained by conducting surveys that involve stopping and questioning drivers at the roadside.

1.2 The purpose of this Advice Note is to provide up-to-date guidance on undertaking a roadside interview survey. These can be in the form of questions asked in person at the roadside or through the distribution of postcards.

1.3 The main terms used in this document are explained in Annex 1.

1.4 This Advice Note should be read in conjunction with the Design Manual for Roads and Bridges Volume 12, Section 2, Part 1; The Traffic Signs Manual, Chapter 8 and the Traffic Signs Regulations and General Directions (TSRGD) 2002 and in Northern Ireland, The Traffic Signs Regulations (NI) 1997.

Survey Priorities

1.5 The overriding priority at any RSI is to ensure the safety of those undertaking the survey and the travelling public. The police are an integral part of this exercise as only police constables, or additionally traffic officers in England and Wales, in uniform have the powers to regulate and direct traffic to a census point.

1.6 Following safety, effective site management is the key to maintaining the co-operation of the travelling public. This ensures that the correct balance is struck between the need to collect good quality information, using well-trained staff, and the need to minimise delays to traffic.

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.7 This Advice Note contains information on egal issues in relation to RSIs in England (Annex 2). owever, the legal situation should always be reviewed efore proposals are finalised because of the possibility f changes to legislation and case law.

cope

.8 This Advice Note provides information on rocedures, site layouts and techniques for conducting SIs.

mplementation

.9 This Advice Note should be used forthwith.

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Chapter 2 Survey Planning

2. SuRveY PlANNING

existing Information

2.1 RSIs are expensive and the information is time consuming to collect. Wherever possible, existing information should be used if it is of a suitable age and quality.

2.2 To assist, the Department for Transport (DfT) has developed a National Origin-Destination Transport Survey Databank which can be reached using the Transport Planning links on the DfT’s Transport Analysis Guidance (TAG) website http://www.dft.gov.uk/webtag/

2.3 The locations of RSIs, home interview surveys and public transport surveys are shown on a map base together with dates and contact details. To ensure the databank is kept up to date, organisations are invited to submit details of new surveys using questionnaires provided.

Duplication of effort

2.4 Before undertaking new RSIs, checks should be made with other relevant organisations to avoid duplication of effort. Otherwise the travelling public may be delayed unnecessarily and significant abortive costs incurred. Where traffic orders are required additional time will be needed. This can be required for temporary parking control suspension and to enable temporary use of bus lanes.

Consultations with others

General

2.5 Consultations should begin at least six weeks before the RSIs are planned to start to enable any necessary agreements to be reached. To promote more effective working, it is recommended that all parties involved nominate a single point of contact.

Police

2.6 RSI site layouts and manning requirements must be agreed in advance with the police, or the appropriate division in the Highways Agency if traffic officers are to be used at the survey site. Police officers employed in connection with RSIs are normally providing a ‘special police service’ which is chargeable and a contractual agreement for the payment of appropriate charges

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will be sought. The main focus for officers providing a ‘special police service’ should be to direct traffic at the survey site. Individual police forces may have slightly different requirements and charges will vary. Consultation with the appropriate police force or Traffic Officer Service should start as early as possible in the programme.

Local Highway Authority

2.7 The approval of the local highway authority is required before operating a site on their road. If the use of bus lanes is required it may be required to consult local bus companies and/or public transport authorities.

Householders/Businesses

2.8 Householders and businesses may be affected when interviewing is in progress and, for safety and operational reasons, there may be a need to restrict vehicle access into private driveways and limit on-street parking. Personal visits are encouraged to explain the proposals, rather than leaflets or telephone calls. Any issues of concern can then be addressed. Blocking vehicle access into private property should be as a last resort only – where possible the location of the RSI should be such that these restrictions will not be needed.

Publicity

2.9 Experience has shown that most drivers will co-operate when called for interview. However, good communication before and during the surveys helps to encourage and maintain good public relations.

Advance Publicity

2.10 An announcement is normally made in advance, possibly in the form of a press release, to inform the travelling public about the purpose of a survey (or programme of surveys) and the benefits the results will bring.

2.11 Press releases may attract media interest, particularly from local newspapers and radio stations. These opportunities can be used to further promote the surveys and convey important messages about safety and the intention to minimise traffic disruption through effective site management. Dates and locations of individual sites should not be disclosed otherwise

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Chapter 2 Survey Planning

drivers might divert from their normal routes and invalidate the survey results.

2.12 The use of mobile telephones has significantly increased the possibility of drivers reporting site locations to local radio stations. Editors should be encouraged not to disclose this information.

2.13 An example press release is shown at Annex 3.

Site Visits

2.14 If requests for site visits are received from the media, suitable control measures must be put in place to ensure that the safety of the operatives on site, the general public and the visitors to the site is not compromised.

members of Parliament

2.15 It is courtesy to notify Members of Parliament (MPs) and Members of Local Assemblies (MLAs) or equivalent in Northern Ireland, Scotland and Wales in advance about RSIs that might affect their constituents.

Timing

2.16 Unless specifically designed to do so, surveys should avoid periods affected by public holidays, including bank holidays and school holidays. They should also avoid other local events, such as conferences, major sporting events or market days, etc. Normally, surveys should be confined to periods that reflect typical traffic flow conditions in the area. The periods generally accepted as most suitable are the spring and autumn (i.e. April, May, June, September and October).

elections

2.17 It is sometimes not possible to undertake surveys during election campaigns. Restrictions may vary depending on the type of election, the commissioning authority and by local highway authority area.

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TIoNS AND lAYouTS

Chapter 3 Interview Site locations and layouts

3. INTeRvIeW SITe loCA

locations

3.1 Interview stations should always be located on the public highway, not on private land. Not only would it be likely to considerably increase the cost of the survey and delay the survey while access rights are obtained, but potentially remove the legal powers of any police/traffic officer controlling traffic for the survey.

3.2 Surveys should be located where accident risks, obstruction and traffic delays are minimised when vehicles are stopped on or near the carriageway. A site with a by-pass lane is preferred, although for single carriageways this will depend on the availability of a suitable lay-by or a road width of at least 10m.

3.3 For safety reasons, and to reduce the risk of imposing unnecessary delays to drivers using other routes, interview sites should be located well away from junctions, although in urban areas this may not be possible. When planning the location of interview sites, the presence of bus stops, shop frontages and driveways etc. should be avoided. Ideally sites should be located on a straight and fairly level stretch of road and hills with steep gradients should be avoided.

3.4 A clear sight distance to the initial sign warning of the presence of the survey ahead of up to 500m is desirable in built up areas, and 800m on rural roads, particularly where traffic speeds are above 50mph. If these distances cannot be achieved, then extra safety measures, such as more signs, may be agreed with the police.

3.5 On single carriageway roads, Stop/Go working, that is where all traffic is stopped at the ‘Census Point’ and the drivers at the head of the queue are interviewed and the queue of traffic is then released, can be used at locations where it is not possible to provide a by-pass lane. On very narrow roads where traffic in the non-interview direction may need to be brought to a stop by police control or the use of STOP/GO board(s), additional signing will be required.

3.6 Surveys may be conducted on dual carriageway roads, though the reduction of traffic speed may present difficulty. In such cases it is essential that signing is adequate and sufficient warning of the site is given, and that vehicles are constrained to a single lane prior to the sampling line to reduce traffic speed to about 20mph.

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3.7 Interview surveys must not be carried out on the main carriageway of a motorway. If appropriate, interviews may be conducted on an entry slip road to a motorway or dual carriageway and a layout illustrating the signing at a survey site on an entry slip road is included as Plan SV7 in Annex 4. For this option to be adopted, vehicles, particularly heavy goods vehicles, having stopped at the interview site, must be able to attain sufficient speed to merge safely with mainline traffic. This should be determined as part of the site-specific risk assessment.

3.8 In addition, interview surveys must not be carried out on an exit slip road of a dual carriageway unless there is no alternative location for conducting the survey. A survey on an exit slip road will almost inevitably lead to queuing on the main carriageway and therefore traffic management on the approach to the site on the main carriageway should use the principles for approach signing shown in Plans SV3 to SV6, including adequate warning of queuing traffic ahead.

3.9 For studies requiring information about motorway traffic movements only, slip road surveys avoid imposing unnecessary delays on drivers using the surrounding local public highway network.

3.10 Arrangements for undertaking survey sites on motorway entry slip roads can be more complicated and time consuming when compared to other roads, particularly if temporary traffic regulation orders are required. Survey organisers are advised to consult with the highway authority as early as possible in the survey planning process about their procedures for sanctioning work on a particular motorway.

3.11 Temporary orders will not be required if a motorway slip road site involves only partial closure of the carriageway and traffic is allowed to use the remaining part of the carriageway in the usual way (carriageway is defined as ‘that part of a motorway which is constructed with a surface suitable for the regular passage of vehicular motor traffic along the motorway’).

3.12 The Highways Agency is responsible for nearly all of the motorway network and persons requiring authority to work or stop on that network must seek permission and obtain a motorway pass. Strict controls are applied to the issue of passes.

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Safety Clearances

3.13 Survey staff will usually have their backs to passing traffic and the presence of vehicle wing mirrors is a particular concern. Therefore, the sideways safety clearance should always be a minimum of one metre with the edge facing the survey staff clearly marked with low resistance rope or safety tape. The arrangement adopted should be the subject of a site-specific risk assessment.

3.14 If minimum safety clearances cannot be achieved, the operation will need further consideration in terms of its location in order to provide a safe system.

Site layouts

3.15 Chapter 8 of the Traffic Signs Manual gives guidance to those designing and operating temporary traffic management at road works and other temporary situations, and Chapter 8 should be read in conjunction with this document.

3.16 The nature of the survey work and the limited road space available at selected sites mean that, generally, it is not possible for the traffic management layouts at survey sites to conform fully with the general road works traffic management plans given in Chapter 8. A site-specific risk assessment should be undertaken whether or not the temporary traffic management at a site conforms with the plans given in Chapter 8 (see paragraph 3.27).

3.17 Plans showing the signing for survey sites and the associated principles are included in Annex 4 of this document. These plans and associated principles supersede those included in Chapter 8: Part 1, Design, Section D3.26.

3.18 The decision whether to conduct interviews from the nearside or offside should be based on a site-specific risk assessment. Examples of both options are shown in the plans in Annex 4.

3.19 All the signs used at interview sites must conform to the Traffic Signs Regulations and General Directions (the ‘Regulations’) or they must be specifically authorised. Authorisations and approvals, where required, need to be procured through the highway authority.

3.20 The ‘other danger ahead’ sign to diagram 562 and ‘Census’ plate to diagram 563 warn of a traffic census or survey at which roadside interviews are being conducted.

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1 The ‘SLOW CENSUS POINT’ sign to diagram 1, ‘CENSUS STOP if directed’ sign to diagram 0.1, and also the ‘STOP AT CENSUS POINT’ sign diagram 830, can be used only at the approaches a site where a driver may be stopped for interview connection with a traffic survey approved by the cretary of State and, where appropriate, also by the hway authority and the police. Only a police officer

a traffic officer may legally stop or direct traffic at a rvey site.

2 The diagram 7001 ‘road works’ sign with the urveying’ plate variant to diagram 7001.1 is used r the protection of survey teams working on or very ar the carriageway where the carriageway is not structed.

3 Some local discretion in the application of porary signs may be necessary for optimum safety

d operational efficiency, depending on the traffic flow, eeds, type of road and information required on the ture of the survey. Surveys may need to be carried out conditions where it is not possible or appropriate for ffic to be funnelled into a single lane of slow-moving ffic, or stationary traffic at signals.

4 As part of the design process, the site should checked to ensure that signs can safely be commodated and any necessary vegetation trimming undertaken in advance of the survey.

5 Once the signing plan for the interview site has en designed, it shall be forwarded to the relevant hway authority for their comments.

6 During the course of the survey, regular checks ould be made of the approach signing and coning to sure that they remain fully effective. These checks ould be recorded in the site diary.

te-Specific Risk Assessment

7 All survey sites present an obstruction on the hway and it is essential that they are subject to a site-

ecific risk assessment.

affic Flows

8 Guidance on traffic flows is given in Chapter 8, r example, Section D3.4 gives information on the ximum throughput at a site before queuing is likely develop.

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Traffic Queues

3.29 Managing congestion is dealt with in Annex 7. It is recommended that, as part of the survey design process, comprehensive traffic data is obtained to calculate the impact of the survey on traffic at the site and to enable a prediction of queue lengths. The design should minimise such queuing and delay to traffic. See also paragraph 3.28.

3.30 The siting distance of the first sign should be beyond the anticipated end of the queue. The length of the queue should be monitored and additional warning signs to diagram 562 ‘other danger ahead’ with supplementary plate ‘Census’ to diagram 563, or a traffic queues sign to diagram 584 with a supplementary plate ‘Queues likely’ to diagram 584.1, should be used.

3.31 Additional signs should be used, as appropriate, in consultation with the police, particularly on roads for which the national speed limit applies.

3.32 Variable Message Signs (VMS) provide a higher visual impact to passing motorists than static signs and are less likely to be missed. The use of temporary VMS (typically trailer-mounted) may be considered as an addition to fixed signs to warn of queuing traffic ahead. Any messages displayed on these signs must comply with regulations 53(1) and 58, and Schedule 15 to the Regulations.

Temporary Speed limits

3.33 The aim on all roads is to reduce the speed of vehicles approaching an interview station to about 20mph in the vicinity of the sampling line by appropriate signing and coning.

3.34 The implementation of a temporary mandatory speed limit should be applied unless a site-specific risk assessment indicates that this is not required. Methods of enforcing a mandatory temporary limit should be discussed with the police and the decision of whether the temporary speed limit is to be mandatory should follow this discussion with the police on enforcement methods. Further guidance on temporary speed limits is given in Chapter 8: Part 1, Design, Section D3.7.

3.35 A limit 20mph below the permanent one, with a minimum limit of 20mph, is recommended if forward visibility at the site is good. However, if forward visibility is poor and/or traffic flows are likely to be low, and thus likely to result in fast moving traffic, then a temporary speed limit 30mph below the permanent one is advised. At survey sites on dual carriageways subject

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to the national speed limit, a temporary mandatory speed limit of 40mph is recommended. Examples of the siting of speed limit signing for the imposition of a mandatory temporary speed limit on single and dual carriageway roads are shown in the plans in Annex 4.

3.36 A Temporary Traffic Regulation Order needs to be obtained if a mandatory speed limit is to be imposed at a site – see paragraph A2.12.

lighting

3.37 All signs shall be either reflectorised and/or illuminated to conform with the requirements of TSRGD. All lamps should be kept clean and in good working order.

3.38 For safety reasons, illumination of signs must be only by electrically powered lamps.

3.39 Temporary floodlighting should be provided to the appropriate standard such that work can be carried out in safety, giving visual emphasis to the interviewers and police officers, and to enable road users to pass safely through the site. Special attention should be given to the orientation of the lighting units to ensure that drivers are not dazzled.

3.40 Warning lights (road danger lamps) complying with the Regulations should be used to indicate the limits of the obstruction and the path vehicles should take. The lamps should be located in accordance with the principles given in Chapter 8.

Weather

3.41 If visibility is reduced due to fog or heavy rain then for safety reasons it may be necessary to suspend operations for a time or close down the site.

Bilingual Signs

3.42 It is a requirement for surveys conducted in Wales that bilingual signs are used. Welsh translations of signs used at survey sites may be obtained from www.traffic-wales.com/traffic_signs

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RATIoN

Chapter 4 Staffing and Site operation

4. STAFFING AND SITe oPe

Survey Staff

4.1 The following list is a guide to the likely survey staff required at an interview station which will vary depending on vehicle flow:

• survey manager with overall responsibility for an RSI programme;

• site supervisor responsible for running an individual site;

• assistant site supervisor to act as co-ordinator, extra interviewer or enumerator, usually only required at very busy sites;

• typically in the range of three to eight interviewers;

• two enumerators for manual classified count;

• relief staff to provide rest breaks for interviewers and enumerators;

• one or two police officers/traffic officers to direct traffic; and

• appropriately trained staff to carry out traffic management duties.

Training

4.2 Staff should be provided with a survey manual providing details about the survey, the duties involved, roles and responsibilities, the associated health and safety requirements and detailed instructions on how to complete the survey questionnaire and the manual classified count form. The forms could be either paper or electronic.

4.3 Staff should be trained as a group as near to the date of the surveys as possible. Training may consist of mock interviews within the group and, if possible, a short practical period on a public highway classifying vehicles.

4.4 An example questionnaire and manual classified count form are included at Annex 5.

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Site Supervisor

4.5 The site supervisor should have the following roles and responsibilities:

• the survey site, including checks of site operations;

• the survey staff and their safety;

• overall responsibility for data quality, including sample rates by vehicle class;

• keeping site diaries up to date;

• monitoring individual staff member performance;

• appointing a deputy if absent from site;

• liaison with enforcement officers; and

• recording any changes and events during the survey period.

Arrangements on Site

4.6 Staff should arrive for duty up to one hour before the commencement of the survey as directed by the site supervisor. This allows time for the supervisor to issue final instructions before interviewing starts.

4.7 Staff should wear comfortable and practical clothing suitable for all weather conditions. Interviewing normally continues in most weather conditions unless general safety is compromised. During the survey period the traffic count must run continuously regardless of any interruptions to the interviews. Hats rather than hoods are more suitable in cold weather as they maintain good visibility.

4.8 For their own safety and the safety of others, it is important that all personnel working on or near the carriageway must at all times wear suitable personal protective equipment (PPE) including high visibility garments. Details are given in Chapter 8: Part 2, Section O6.3.

4.9 Facilities should be identified in the local area for staff use. Access to proper toilet facilities, etc. should be in a convenient location.

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4.10 A rota for rest breaks is required that ensures the maximum period for interviewing does not normally exceed two hours. A suggested rota is one hour interviews, one hour count, one hour interviews, and then one hour break taking into account the skills of staff, for example, enumerators may not have the right skills for undertaking interviews. Staff should not be expected to work excessive hours as fatigue reduces accuracy and increases the risk of accidents in a potentially dangerous environment.

4.11 It is usual to install a temporary Automatic Traffic Counter (ATC) at a proposed RSI location for a one-or two-week period to encompass the planned survey date in order to identify normal traffic patterns where this data is not available from other sources. ATCs should be classified and provide two-way flows. When surveying on-slips, the comparable off-slip should be covered by an ATC as well.

Interview Procedure and Questionnaire

4.12 An interview should be undertaken as efficiently as possible so that any delay is minimised. Ideally the time between a driver leaving and rejoining the main traffic flow, including the interview, should not exceed three minutes.

Figure 4.1: Recommended interview steps

4.13 Compliance with the requirements of the Data Protection Act is a matter for individual organisations to consider when planning a survey programme. However, under the Act, drivers called for interview must be provided with a Fair Processing Notice (FPN) prior to any request for information.

Step 1Very brief introduction

(Data Protection Act, etc.)

Step 2RSI questions

Step 3Hand out background leaflet

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4.14 The FPN can be delivered verbally in a brief introduction giving the name of the data controller, the purpose or purposes for which the information is to be used and any other disclosures considered appropriate under the Act. Drivers should also be informed that information is given on a voluntary basis.

4.15 For drivers willing to co-operate, questions should be asked in a precise and unambiguous way and require short answers, while at the same time fulfilling the objectives of the survey.

4.16 To avoid disruption to site operation, interviewers should avoid becoming engaged in long conversations with drivers. It is recommended that a leaflet is given out that confirms the details of the FPN and provides additional information about the surveys as appropriate.

4.17 An example leaflet is included at Annex 6.

Traffic management Team

4.18 For safety and operational reasons, it is recommended that survey staff will not become directly involved with traffic management at the site unless specifically trained to do so. This activity should always be undertaken by specialist quality assured contractors. Some local highway authorities may insist that a suitable contractor is selected from their approved list. On the Highways Agency network in England, the organisations engaged in traffic management operations are required to comply fully with the requirements of the National Highway Sector Schemes which are training qualifications for supervisors and operatives. The Sector Schemes relevant to traffic management at survey sites are Schemes 12B and 12D. Details are available on the United Kingdom Accreditation Service (UKAS) website, www.ukas.com. See also Chapter 8: Part 2, Section O6.2.

4.19 The site supervisor retains overall control of the site once established. However, the traffic management team should be on call throughout the survey period in case adjustments are required to the layout to address a safety issue, or the site needs to be suspended or closed down.

Police officer or Traffic officer

4.20 The police officer or traffic officer, as appropriate, is responsible for the control of traffic, its movement through the site and for its entry and exit from the interview bay. Police officers are normally employed on a ‘special policing duties’ basis. As such the operation of the traffic count should be their focus on site.

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Adequate provision to cover rest breaks should be made in order to maintain survey continuity. If for any reason the officer is absent from the site, interviewing must be suspended.

4.21 More than one police or traffic officer may be required to regulate traffic at a particular site, especially where there are safety considerations or congestion through the site can be expected.

4.22 All decisions affecting site operation should be taken by the site supervisor in conjunction with the police or traffic officer to avoid confusion.

Site operation

Sites with By-pass Lane

4.23 The police or traffic officer stands in the carriageway in front of the sampling line. The interviewer furthest from the officer indicates when the bays are empty and that he/she is ready to commence. At sites with two officers it may be necessary to co-ordinate the stopping of vehicles in for interview and the release of vehicles back into traffic.

4.24 It is important that a random sample of vehicles is obtained as far as possible. The officer directs the first and following vehicles in the main traffic stream into the interview station until all the bays are full. Vehicles not required for interview are then directed into the by-pass lane.

4.25 A bias in the sample may be introduced if faster moving vehicles or heavy goods vehicles are ignored. Specific vehicle types should be directed into the station to increase the sample size if required.

4.26 There is tendency for interviewers to ‘drift’ along the bay and, to maximise the number of interviews, staff must reposition themselves correctly to meet incoming vehicles.

4.27 Interviewers must not move cones to allow waiting drivers to leave the bay and must avoid doing anything that could be construed as directing traffic.

Stop/Go Sites

4.28 At Stop/Go sites, the police or traffic officer should stand at the side of the interviewer furthest from the approaching traffic and stop the required vehicle as it reaches him, bringing those following to a halt. Interviews may then proceed.

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Signal Controlled Junctions

4.29 At signal controlled junctions it may not be possible to ask drivers questions directly. In these circumstances self completion postal questionnaires could be used.

Time Periods

4.30 Generally, surveys are carried out for either 12 or 16 hour periods, between 0700 and 1900 and 0600 and 2200 hours respectively, or for 24-hour periods. To ensure that information collected is useful for a range of different purposes, it is recommended that survey periods should not be less than 12 hours. In order to assist with processing it is suggested that forms be collected from interviewers half hourly.

Site Diaries

4.31 There may be a time gap between the data collection and processing stages of a survey programme and, in addition, these stages may be carried out by different organisations. It is, therefore, extremely important that any events affecting the data collection are accurately recorded on the day of survey to avoid problems later. It is normally the responsibility of the site supervisor to ensure proper records are kept, usually through the completion of a Site Diary. Site diaries should contain information such as:

• when surveys go smoothly;

• site closures;

• changes in methods;

• weather (with times);

• police/traffic officer presence (with times);

• site hours;

• team size;

• sample size;

• traffic flows;

• site number, location and direction;

• postcard serial numbers and times of despatch to drivers;

• any other information as appropriate.

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4.32 Site supervisors should ensure that the site number, site location and direction of interview are clearly recorded. While site locations and layouts are agreed with the police in advance, there is sometimes a need to make changes on the day for unexpected safety or operational problems. Failure to note these changes will inevitably lead to confusion during the processing stage. Diaries should be used as a record of all events on site, and not just problems or issues to be solved, therefore, all diaries should contain at least basiccomments on the nature of the survey and its location, etc.

4.33 Complaints and issues raised by members of the public should be noted in site diaries to assist the commissioning authority in dealing with the public’s concerns as quickly and efficiently as possible.

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G

Chapter 5 Contingency Planning

5. CoNTINGeNCY PlANNIN

5.1 Even with careful planning, traffic congestion can become a problem, particularly during peak periods. Dealing with these problems requires careful judgement and a contingency plan should always be developed in advance. To help plan effectively, details about existing traffic conditions will be required.

5.2 Suspending operations temporarily is preferable to subjecting the travelling public to unacceptable delays. The latter may lead to the police closing down the site and the loss of goodwill on behalf of the travelling public may rule out any possibility of returning to the same location in the future.

5.3 When a survey has been suspended, it is recommended that all non-essential staff leave the immediate vicinity of the site. Groups of people wearing high visibility jackets may distract drivers, causing congestion to clear less quickly. In addition, it is recommended that ‘STOP AT CENSUS POINT’ and ‘CENSUS STOP if directed’ signs should be laid down to avoid drivers expecting to be stopped while the queue is cleared.

5.4 A contingency plan is site-specific and should be implemented by the site supervisor, in consultation with the police or traffic officer.

5.5 For instance, the contingency plan may be initiated when queues reach a pre-determined point. To avoid confusion, the end-of-queue point should be clearly marked on the site layout plan. At busy sites, queue lengths should be monitored by a separate member of the survey team who keeps in touch with the site supervisor by mobile telephone. For safety reasons, the first sign should be beyond the end of the queue; see the signing principles given in Annex 4.

5.6 It may be reasonable not to implement a contingency plan if the end of the peak period is in sight and removing traffic management would be a major task. In addition, delays may exceed normally acceptable levels when it is clear that sufficient traffic is passing through the site to feed a bottleneck to capacity further down the road.

5.7 Information on managing congestion is provided in Annex 7.

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meTHoDS

Chapter 6 Alternative Survey methods

6. AlTeRNATIve SuRveY

General

6.1 At a specific location RSIs provide the best source of information about journeys. Alternative survey methods are required where concerns about safety and congestion are not easily overcome. There are a number of alternative methods for collecting origin and destination information. None of the methods collect identical data and sample bias, lack of journey purpose or only partial origin destination information can occur depending upon survey method.

Survey Redesign

6.2 A cordon of surveys may be used instead of a survey on a road that is unsuitable for use as a survey site. The same information may be obtained from surveys at several locations on the surrounding roads and by possibly asking a ‘screening’ question to confirm the relevance for participation in the survey. This method may well delay drivers not intending to pass through the original location and involve extra data collection and processing costs.

Self-Completion Postcard Questionnaires

6.3 Postcard questionnaires are handed out at locations where drivers normally slow down, such as on the approach to roundabouts or at traffic signals. Drivers complete the questionnaires later and return them by post. In comparison with face-to-face interviews, delays may be significantly reduced. The need for lane closures on dual carriageway sites may be avoided, leading to further delay savings.

6.4 The two major disadvantages of postcard questionnaires are the low return rates, anything from 5% to 50% and also sample bias from an imbalance in responses from particular sections of the public, especially commercial vehicle drivers. To maximise the number of responses, it is recommended that postage is pre-paid, also a prize draw may increase participation rates.

6.5 Responses take longer to be collected than face-to-face interviews as they rely on respondents choosing to post a card and then the normal postal delay.

6.6 Privacy of responses on postcard surveys is important and consideration should be given to providing envelopes or postcards with gummed edges

November 2009

that can be sealed thus concealing survey information while in transit.

6.7 The questionnaire should include the FPN (paragraph 4.13) and further details about the survey as appropriate. This should include a serial number on the card, and a list in the site diary of times that batches of cards were distributed.

6.8 It is recommended that an additional question of ‘where were you given this card’ be included alongside the serial number for each card to assist in tracking survey locations on large survey sites.

Registration Number Surveys

6.9 Registration number surveys have several disadvantages over RSIs. The journey information lacks detail about purpose and the ultimate origin and destination of the trip. Also, the processing of the information can be complicated and time consuming. The advantages are that drivers are not inconvenienced and there is a lower unit cost of observation.

6.10 Registration number surveys are sometimes used for limited validation of origin and destination information in small or closed systems where RSIs are difficult to carry out. For example, they may be useful for checking movements using alternative routes or to provide entry and exit information for small junction or road improvement schemes.

6.11 Registration number surveys may also be useful in combination with RSIs, for example, to provide information on journeys using a network of motorways serving a large conurbation.

6.12 Journey information for traffic joining and leaving a motorway within the conurbation may be obtained from RSIs on junction entry slip roads. The registration number surveys are used to identify the entry and exit points of traffic passing through the conurbation, as interviewing on the motorway mainline is not permitted (see paragraph 3.7). The registration number surveys can also provide journey time information for through traffic.

6.13 Mobile Automatic Number Plate Recognition (ANPR) cameras can also be considered as they greatly improve accuracy over manual number plate surveys.

6/1


S CoDING

Chapter 7 Sampling and Address Coding

7. SAmPlING AND ADDReS

Sampling

7.1 For RSIs, vehicle samples should be selected at random. In order to achieve this, vehicles should be directed to the interview bays as soon as they are available, slower vehicles should not be chosen in preference to faster ones.

7.2 The number of interviews needed to obtain a representative sample of vehicles using a particular route is dictated by the needs of a particular study. Sample size is the number of vehicle drivers interviewed in any one period, and not the percentage flow in that period.

7.3 An example showing how to estimate the number of interviews required is given at Annex 8.

7.4 This estimate is used to fix the size of the survey team. However, providing more than six interviewers can have a detrimental effect on the sample rate due to the extra time required to fill and empty the interview station.

7.5 As a guide, experience suggests that four experienced interviewers can obtain in excess of 100 interviews per hour on average, although this number is not always achievable due to lack of traffic, traffic management difficulties or bad weather.

7.6 Questions in addition to those highlighted in Annex 5 should be assessed against the reduced sample size achieved when survey lengths increase.

Data Quality and Address Coding Guidelines

General

7.7 The site supervisor is responsible for ensuring that high standards of data collection are maintained. This will ensure that the benefits RSI information can bring are maximised.

7.8 For large survey programmes scheduled to take place over a number of weeks, there are significant advantages in data collection and processing running in parallel. Regular feedback to staff on site helps with the overall quality control process.

7.9 The use of electronic logging devices is recommended as it can offer more accurate collection

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November 2009

nd remove the need to transpose the collected data nto digital format. In addition, the use of electronic azetteers can also significantly increase the speed at hich the information is collected, reducing delays to otorists.

ddress Coding Guidelines

.10 Address information should be as detailed as ossible. Normally, it is not acceptable to obtain only ostcode information. Postcodes should be collected as art of a detailed address for identification purposes.

.11 Clear and unambiguous handwriting is also ssential on site as processing will generally be carried ut by someone else. While there is often pressure o complete interviews quickly, especially during nclement weather, efforts should be made to ensure that riting is legible.

.12 Generally, abbreviations should be avoided. At ites intercepting drivers heading towards a town, parts f an address may be repetitive so there is a temptation o abbreviate, for example, Nor for Northampton. owever, some abbreviations may be allowed, such as d., St. and Ave.

.13 Addresses such as ‘Rubbish Tip’ may make ense at the roadside, but may well cause difficulties ater. In cities, for example, ‘Garage’ in Old Kent oad is ambiguous as there may well be more than ne; the locality is required. There are duplicated town ames, for example, Ashford, Farnborough, Kingston, illingham, which are made unique by the county ame.

.14 Driving lessons, car testing or country drives are xamples of journeys without a destination. These can e difficult to deal with on site. Interviewers should try nd identify the furthest points reached before or after he site. Postal addresses will probably be difficult to pecify, but street names, villages or main landmarks an usually be obtained.

.15 When drivers are leaving the country, the address f their point of exit or entry, i.e. seaport or airport, hould be recorded.

.16 Ask the driver to spell unfamiliar place names.

7/1


Chapter 8 References

8. ReFeReNCeS

1. Design Manual for Roads and Bridges (DMRB) Volume 12, Section 2, Part 1, Traffic Appraisal inUrban Areas.

2. Chapter 8 of the Traffic Signs Manual: Traffic Safety Measures and Signs for Road Works and Temporary Situations.

3. The Traffic Signs Regulations and General Directions 2002 (SI 2002 No. 3113).

4. Traffic Management Act 2004.

5. United Kingdom Accreditation Service (UKAS). Scheme 12B. Sector Scheme document for static temporary traffic management on motorways andhigh speed dual carriageways including on-line widening schemes.

6. United Kingdom Accreditation Service (UKAS). Scheme 12D. Sector Scheme document for static temporary traffic management on Rural and Urban Roads.

November 2009 8/1

November 2009


9. eNQuIRIeS

9/1

Chapter 9 enquiries

All technical enquiries or comments on this Advice Note should be sent in writing as appropriate to:

Director Network Planning and Performance Highways Agency 123 Buckingham Palace Road London D GINGELL SW1W 9HA Director, Network Planning and Performance

Director, Major Transport Infrastructure Projects Transport Scotland Buchanan House 58 Port Dundas Road Glasgow A C McLAUGHLIN G4 0HF Director, Major Transport Infrastructure Projects

Chief Highway Engineer Welsh Assembly Government Llywodraeth Cynulliad Cymru Crown Buildings Cathays Park Cardiff S C SHOULER (BSc(Hons), C.Eng.MICE) CF10 3NQ Chief Highway Engineer

Director of Engineering The Department for Regional Development Roads Service Clarence Court 10-18 Adelaide Street Belfast R J M CAIRNS BT2 8GB Director of Engineering


SeD IN RoADSIDe veYS

A1/1


November 2009

ANNeX 1 DeFINITIoNS u INTeRvIeW SuR

General

A1.1 This Annex defines the principal terms and concepts associated with roadside interview surveys.

Definitions

By-pass lane: A traffic lane established with cones to allow non-interviewed traffic to pass the interview station.

Census point:The position on the highway where the interviewing and counting takes place.

Cordon: A ring of census points surrounding an area that is designed to intercept the majority of traffic entering or leaving that area.

Highway Authority: Is defined by the New Roads and Street Works Act 1991, as having the meaning given in the Highways Act 1980 the meaning of ‘roads authority’ as given in the Roads (Scotland) Act 1984.

Interview Bay: The section of the site where vehicles are stopped for interviews to take place. The number of bays may vary between sites and peak and off-peak times.

Interview Site: The section of road covered by the traffic management (traffic signs and cones) and including the interview station.

Roadside Interview Survey: A survey at a specific point on the highway network where a sample of drivers is stopped and asked by interviewers to volunteer to answer questions about their journeys. The information usually requested from each driver includes the full address of the start (origin) and finish (destination) points of their journey and the reason (purpose) for making the journey.

Sampling Point: The location prior to the interview station where a police officer selects vehicles for interview and directs them into the interview station. At a Stop/Go site, this will also be the ‘Census Point’.

Screen line: A line of census points across an area that is designed to intercept all traffic going from one side of the area to the other.

Secretary of State: The Secretary of State for Transport, the Department for Regional Development (Northern Ireland), the Transport Scotland or the Welsh Assembly Government, as appropriate.

Stop/Go Site: An interview site without a by-pass lane where all traffic is stopped at the ‘Census Point’ and the drivers at the head of the queue are interviewed and the queue of traffic is then released.

Traffic Authority Has the meaning given by section 121A of the Road Traffic Regulation Act 1984.

Traffic Count:A count undertaken to determine the number of vehicles using a particular road. Counts can be undertaken manually (counted by enumerators) or automatically (counted by machine) as follows:

• Manual Classified Count: a count that breaks down traffic flows by vehicle type. Classified counts are required at every roadside interview site, and on minor parallel roads within the corridor not included in the interview programme, to expand the interview sample to the total traffic flow in the corridor as a whole; and

• Automatic Traffic Count: a count used to monitor traffic flows over longer periods to provide information about the relationship between traffic on the survey day and longer-term flow levels. All roadside interview sites should normally be included in automatic count programmes for at least two weeks.



Traffic officer: Traffic officers in England are generally designated by the Secretary of State and have jurisdiction over such roads as may be specified in that designation. The Traffic Management Act 2004 gives traffic officers the power on roads for which the Secretary of State is the traffic authority, to:

• stop and direct vehicles, cyclists and pedestrians; and

• place temporary traffic signs to warn or direct traffic.

November 2009A1/2


WoRK FoR eNGlAND

Annex 2 legal Framework for england

ANNeX 2 leGAl FRAme

General

A2.1 This Annex does not make reference to all legislation that may be applicable to anyone engaged in RSIs as anyone so engaged needs to comply with all current applicable legislation in any case. Some of the major legal requirements that anyone engaged in RSIs in England should take into account are indicated below. Equivalent legal requirements are likely to apply to Wales, Scotland and Northern Ireland. The information provided is not meant to be exhaustive and is intended for guidance only. The legal requirements should always be reviewed before proposals for RSIs are finalised and all applicable legislation should be complied with.

Human Rights and Data Protection

A2.2 The European Convention on Human Rights, which became part of UK law with effect from 2 October 2000 under the 1998 Human Rights Act, and the Data Protection Act 1998 are very complex pieces of legislation. Anyone engaged in RSIs will need to consider the requirements of both these Acts and how compliance should be achieved for their specific survey programme.

Health and Safety

A2.3 Health and safety at work is regulated mainly by the Health and Safety at Work etc Act 1974 (HSWA).

A2.4 This HSWA requires an employer to ensure, so far as is reasonably practicable, the health and safety at work of all employees and others who may be affected by his actions. Any injured persons or their dependants may be able to sustain a claim for damages if negligence or breach of statutory duty can be proved.

A2.5 In terms of undertaking a roadside interview survey, it is imperative from the outset that all those involved should have a clear understanding of how compliance with the HSWA is to be achieved.

Traffic Directions for the Purposes of a RSI

A2.6 Section 6 of the Traffic Management Act 2004 (TMA) gives traffic officers the power to stop a vehicle or to make it proceed in, or keep to, a particular line of traffic for the purposes of a traffic survey of any description which is being carried out on or in the vicinity of the road. Section 7 of the TMA give traffic

November 2009

officers similar powers to a police constable to place and maintain traffic signs on the road.

A2.7 The powers of a traffic officer are subject to certain limitations. The limitations are:

(a) that the powers may only be exercised in relation to those roads over which the traffic officer has jurisdiction or under the direction of the Chief Officer of the Police for the area or with the consent of the local traffic authority; and

(b) that they are used for the purposes of:

• maintaining or improving the movement of traffic on those roads over which the traffic officer has jurisdiction;

• preventing or reducing the effect of anything causing (or which has the potential to cause) congestion or other disruption to the movement of traffic on such a road;

• avoiding danger to persons or other traffic using such a road (or preventing risks of any such danger arising);

• preventing damage to, or to anything on or near such a road;

• or that they are used for a purpose incidental to one of the purposes set out above.

A2.8 The Road Traffic Act 1988 (RTA) requires any person to follow the direction of a police constable to stop a vehicle or to make it proceed in, or keep to, a particular line of traffic for the purposes of a traffic survey of any description which is being carried out on or in the vicinity of the road.

A2.9 Neither a police constable nor a traffic officer can give a direction requiring a person to provide information for the purposes of a traffic survey and both the power of the police constable and the traffic officer to direct traffic for the purposes of a traffic survey should be exercised as not to cause any unreasonable delay to a person who indicates an unwillingness to provide any information for the purposes of the traffic survey.

A2/1


Annex 2 legal Framework for england

Insurance

A2.10 Employers should ensure that they have insurance against their liability for personal injury to their employees as provided for by the Employer’s Liability (Compulsory Insurance) Act 1969.

A2.11 Employers should also ensure that they have the appropriate level of public liability insurance.

Temporary Traffic Regulation orders

A2.12 Under certain circumstances it may be necessary to obtain temporary traffic regulation orders before a survey site can go ahead. For example, orders may be required to suspend parking bays, prevent loading and unloading or impose a temporary speed limit. Advice on the need for temporary orders should be sought from the appropriate highway authority as part of the normal survey planning process.

A2.13 Orders are made under Section 14 of the Road Traffic Regulation Act 1984. The Road Traffic (Temporary Restrictions) Procedure Regulations 1992 lay down the procedures to be followed in processing temporary orders under Section 14. However, for obvious safety and operational reasons, RSIs must not be conducted on the mainline of a motorway (see paragraph 3.7).

A2.14 Orders must be issued by the appropriate highway authority. A minimum of eight weeks is normally required before the start of works to draft the Order and sufficient time should be allowed in the survey planning process.

Surveys on motorways

A2.15 The Motorway Traffic (England and Wales) Regulations 1982 (the Regulations) make provision for the way in which motorways are used by traffic. The Regulations provide a relaxation on the use of motorways in accordance with the Regulations where it is necessary for a person to do so in connection with any inspection, survey, investigation or census which is carried out in accordance with any general or specific authority granted by the Secretary of State.

A2.16 For procedural guidance on undertaking an RSI on a motorway entry slip see Section 3.

November 2009A2/2


Annex 3 example Press Release

ANNeX 3 eXAmPle PReSS ReleASe

TRAFFIC SuRveYS ABouT To START

The Highways Agency announced today that a two-week programme of roadside traffic surveys to assess drivers’ journey patterns will start this week (ending 20 March 2009) at a small number of sites in Hampshire.

This is part of a major survey programme covering London and South East England being carried out jointly by the Highways Agency and Transport for London which started in Autumn 2008.

Highways Agency Project Manager Alan Turner said:

‘When completed, the surveys will provide high quality information on the journeys made by car and lorry drivers over about one third of the area of England. The information will help the Agency to gain an understanding of travel patterns, providing a key input to the development and planning of future investment in the transport system. We hope that the travelling public will co-operate to help us deliver the improvements that they want’.

The surveys involve stopping a sample of drivers and asking them to volunteer to answer questions about their journeys. Each survey site is operated in one direction, on one day only, with interviews expected to take between two and three minutes. Safety will be of paramount importance, with traffic control provided by the police at all site locations. All necessary steps will be taken to minimise delays.

NoTeS To eDIToRS

1. Local news media are requested to refrain from broadcasting the exact dates and locations of the surveys should they become aware of them. This is necessary to avoid drivers changing their normal travel behaviour and distorting the survey results.

2. The surveys will be carried out by contractors experienced in conducting roadside interviews.

3. Explanatory leaflets will be handed out to drivers who want to know more about the surveys, and these will give telephone numbers for enquiries.

4. The Highways Agency is an Executive Agency of the Department for Transport, which manages, maintains and improves the network of trunk roads and motorways in England on behalf of the Secretary of State. It works closely with other transport operators and with local authorities to integrate the trunk road network with the rest of England’s roads and other forms of transport. More information is available at www.highways.gov.uk

November 2009 A3/1


IPleS AND TYPICAl

A

Annex 4 Signing Principles and Typical Site layouts

ANNeX 4 SIGNING PRINC SITe lAYouTS

Signing Principles

A4.1 In this Annex, the terms Detail B, C1 and C2 in the plans and principles refer to coning details given in Table A4.1.

A4.2 At the survey site, the principles are:

• the length of the survey area is given by the formula:

(4 + 8 x the number of interviewers)(m);

except when the survey site is at a traffic signal controlled junction. In this case the length is given by the formula:

(4 + 4 x the number of interviewers)(m);

• coning to Detail C1 is used to mark a guide island through the survey site;

• ‘keep left/right’ signs (610) are used on the off side behind the coning of the guide island to indicate the route traffic should take past the guide island; and to indicate the line of the traffic; and

• a police officer or a traffic officer is required to be in attendance as only a duly authorised officer may legally stop or direct traffic at survey sites.

A4.3 On single carriageway roads:

The following signing is required in the primary direction on the near side upstream of the sampling point:

• a ‘hazard’ sign (562) with supplementary plate ‘Census’ (563) including the distance to the first traffic cone;

• a traffic queues sign to diagram 584 with a supplementary plate (584.1) ‘Queues likely’;

• at least one ‘road narrows’ sign (517) with supplementary plate ‘Single file traffic’ (518);

November 2009

• a ‘CENSUS STOP if directed’ sign (830.1); and

• a ‘CENSUS POINT’ sign (832) located at the far end of the census point;

and in the secondary direction on the near side upstream of the first cone of the survey area:

• a ‘hazard’ sign (562) with supplementary plate ‘Census’ (563); and

• at least one ‘road narrows’ sign (517) with supplementary plate ‘Single file traffic’ (518).

For safety reasons, the siting distance of the first sign should be beyond the anticipated end of the queue. The length of the queue should be monitored and additional warning signs either to diagram 562 ‘other danger ahead’ with supplementary plate ‘Census’, or a traffic queues sign to diagram 584 with a supplementary plate (584.1) ‘Queues likely’ should be used.

4.4 On dual carriageway roads:

The following signing is required in the primary direction on the near side and off side upstream of the sampling point:

• a ‘hazard’ sign (562) with supplementary plate ‘Census’ (563) including the distance to the first traffic cone;

• a traffic queues sign to diagram 584 with a supplementary plate (584.1) ‘Queues likely’;

• depending on the permanent speed limit of the road, between two and four pairs of advanced lane closure signs are required, that is:

A4/1



• wicket signs indicating the closed lane (7202) with distance panel, for example, ‘800 yards’ (7208) on the near side and off side, placed 800m in advance of the first cone of the taper. These signs are repeated, with the appropriate distance plate, at 200 yard intervals to a point 200 yards in advance of the works, i.e. at 600m, 400m and 200m; and

• at least two ‘SLOW CENSUS POINT’ signs (831);

• ‘CENSUS STOP if directed’ signs (830.1) on the near side and off side; and

• a ‘CENSUS POINT’ sign (832) located at the far end of the census point.

For safety reasons, the siting distance of the first sign should be beyond the anticipated end of the queue. The length of the queue should be monitored and additional warning signs either to diagram 562 ‘other danger ahead’ with supplementary plate ‘Census’, or a traffic queues sign to diagram 584 with a supplementary plate (584.1) ‘Queues likely’ should be used.

list of layout Plans

A4.5 The list of plans is as follows:

Plan SV1: Traffic survey on a single carriageway road:

(a) with a lay-by; (b) without a lay-by.

Plan SV2: Traffic survey at a traffic signal controlled junction.

Plan SV3: Traffic survey on a two-lane dual carriageway road with a permanent speed limit of 40 mph or less - interviewing from the nearside:

(a) with a lay-by; (b) without a lay-by.

Plan SV4: Traffic survey on a two-lane dual carriageway road with a permanent speed limit of 50 or 60 mph.

A4/2

Plan SV5: Traffic survey on a two-lane dual carriageway road for which the national speed limit applies.

Plan SV6: Traffic survey on a three-lane dual carriageway road for which the national speed limit applies – interviewing from the nearside.

Plan SV7: Traffic survey on a dual carriageway entry slip road - lane closure at the downstream end of the slip road.

November 2009

Novem

b

volume 5 Section 1

Part 4 TA 11/09

Details B, C1 and C2 used in plans (minimum sizes given)Single Single Dual

geway ermanent limit of or less)

Dual carriageway

road (permanent speed limit of

50 mph or 60 mph)

Dual carriageway

road (national speed limit)

nes mm

spacing 5 m

Cones 750 mm

Cone spacing

1.5 m

Cones 750 mm

Cone spacing

1.5 m

ns

Annex 4

Signing Principles and Typical Site layouts

D

D

D

er 2009

carriageway road (permanent

speed limit of 40 mph or less)


speed limit of 50 mph or more)

carriaroad (p

speed40 mph

Detail B

Notes:

1) During darkness, warning lights to BS EN 12352:2006 should be provided in accordance with Chapter 8, Table A1.3 (Appendix 1).

2) 45o tapers have 1.2m cone spacing, no relaxations.

3) On motorways and all-purpose dual carriageway roads with hard shoulders on which the national speed limit applies, 1m cones will be required for both standard works and works for which relaxations may be applied, for both lead tapers and the facing wall of a lane change.

Cones 450 mm

Cone spacing

1.5 m

Cones 750 mm

Cone spacing

1.5 m

Co450

Cone 1.

Table A4.1 Details B, C1 and C2 used in the pla

A4/3

etail B

Traffic cones(45° tapers have 1.2m spacing, no relaxations)

etail C19m

Traffic cones

etail C2

Traffic cones3m

volume 5 Section 1

Part 4 TA 11/09

Details B, C1 and C2 used in plans (minimum sizes given)Single Single Dual

arriageway d (permanent

peed limit of mph or less)

Dual carriageway

road (permanent speed limit of

50 mph or 60 mph)

Dual carriageway

road (national speed limit)

Cones

450 mm

Cones

750 mm

Cones

750 mm

Cones

750 mm

s (continued)

A4/4

Annex 4

Signing Principles and Typical Site layouts

De

De

De

De


De

De

Novem

ber 2009


speed limit of 40 mph or less)


speed limit of 50 mph or more)

croa

s40

Detail C

method C1:

method C2:

Note:

1) During darkness, warning lights to BS EN 12352:2006 should be provided in accordance with Chapter 8, Table A1.3 (Appendix 1).

Cones

450 mm

Cones

450 mm

Cones

750 mm

Cones

750 mm

Table A4.1 Details B, C1 and C2 used in the plan

tail B


tail C19m

Traffic cones

tail C2

Traffic cones3m

tail B

tail C19m

Traffic cones

tail C2

Traffic cones3m



Dimension Single carriageway road: Permanent speed limit30mph or

less40mph 50mph unrestricted

(60mph)Distance ‘D’ Normal maximum siting distance of the first sign in advance of the lead-in taper in metres.1

100

200

450

450

Distance ‘T’ Length of the cone taper in metres. Width of hazard (metres) 1 2 3 4 5

13 26 39 52 65

20 40 60 80 100

25 50 75 100 125

25 50 75 100 125

Note:

1. (a) The values for the minimum siting distance of the first sign on roads with a permanent speed limit of 40mph or less are greater than those given in the equivalent table in Chapter 8 (Table 5.3 in Part 1: Design). This is because queuing traffic is likely at survey sites and sufficient warning of a queue is necessary.

(b) The distance shown should be used when extensive queuing is not expected. For safety reasons, the siting distance of the first sign should be beyond the anticipated end of the queue. The length of the queue should be monitored and additional warning signs either to diagram 562 ‘other danger ahead’ with supplementary plate (563) ‘Census’, or a traffic queues sign to diagram 584 with a supplementary plate (584.1) ‘Queues likely’ should be used.

TABle A4.2 Distances shown in Plans Sv1 and Sv2

November 2009 A4/5


1

1


Plan Sv1: Traffic survey on a single carriageway road

With a lay-by (a)

Without a lay-by (b)

4+8x

(No.

Inte

rvie

wer

s)

Sampling line

832

3.0

P

P

C1

830.1

Datum

DSee Note 1

T830.1

Datum

3.0

30m

610

610

D

Datum

See Note 1

T See Note 1

B

610

610

B

3.03.0

C1

562

563

See Note 2

584.1

584

670 See Note 3

831

670

517

518

See Note 4

670

See Note 4

563

517

518

562

See Note 2

670See Note 3

670

See Note 5

670

See Note 5

4+8x

(No.

Inte

rvie

wer

s)

Sampling line

832

3.0

P

P

30m

610

C1

B

830.1

Datum

DSee Note 1

T 610830.1

Datum

3.030m

610

610

D

Datum

See Note

T See NoteB

562

563

See Note 2

584.1

584

670 See Note 3

831

670

517

518

See Note 4

670

See Note 5 563

517

518

562

See Note 2

670See Note 3

670

See Note 4

670

See Note 5

November 2009A4/6



Plan Sv1: Traffic survey on a single carriageway road

Notes:

1. Refer to Table A4.2 for the dimensions of D and T.

2. The distance shown on the sub-plate to diagram 563 should be that to the first traffic cone, that is, dimension D.

3. A temporary mandatory speed limit 20 mph below the permanent speed limit, with a minimum of 20 mph, is recommended.

4. For the spacing of speed limit repeater signs see Chapter 8, Part 1: Design, Table 3.4, Note 1.

5. A sign showing the permanent speed limit on the road should be included after the interview site.

6. Additional signing will be required in the non-interview direction on very narrow roads where traffic may be brought to a stop by police control or the use of STOP/GO boards.

7. For safety reasons, the siting distance of the first sign should be beyond the anticipated end of the queue. The location of the end of the queue should be monitored and additional signs should be added if necessary.

November 2009 A4/7



Plan Sv2: Traffic survey at a traffic signal controlled junction

P

562

563

4+4x

(No.

Inte

rvie

wer

s)

831

830.3

832

562

563 5

62

563

DSee Note 1

830.1

Datum

584.1

584

670

670

See Note 2

562

563

See Note 3

See Note 4

670

See Note 5

See Note 3

See Note 4

See Note 5

670

670

670

November 2009A4/8



Plan Sv2: Traffic survey at a traffic signal controlled junction

Notes:

1. Refer to Table A4.2 for the dimension of D.

2. The distance shown on the sub-plate diagram 563 should that to the first traffic cone, that is, dimension D.





November 2009 A4/9



Plan Sv3: Traffic survey on a two-lane dual carriageway road with a permanent speed limit of 40 mph or less – interviewing from the nearside

With a lay-by (a)

Without a lay-by (b)

3.0

830.1

Datum

Sampling line

200m

300m

100m 831

100m

150m

C1

Trafficlanes

Centralreservation

610 7105

831

830.1

670

610

C2

200m

30m

610

C1

45m

300m

275m

350m

25m

670 See Note 2

C1

832

4+8x

(No.

Inte

rvie

wer

s)

P

7202

7208

P

250m

562

563

670

7202

7208

584.1

584

See Note 1

See Note 3

3.0

830.1

Datum

Sampling line

200m

300m

100m 831

7202

100m

150m

P

832

C1

Trafficlanes

Centralreservation

610 7105

831

830.1

670

610

C2

200m

4+8x

(No.

Inte

rvie

wer

s)

30m

610

C1

45m

300m

275m

350m

25m

670

C1

7208

P

562

563

670

7202

7208

584.1

584

250mSee Note 1

See Note 2

See Note 3

November 2009A4/10



Plan Sv3: Traffic survey on a two-lane dual carriageway road with a permanent speed limit of 40 mph or less – interviewing from the nearside

Notes:


2. For the spacing of speed limit repeater signs, see Chapter 8, Part 1: Design, Table 3.4, Note 1.



November 2009 A4/11



Plan Sv4: Traffic survey on a two-lane dual carriageway road with a permanent speed limit of 50 or 60 mph

3.0

Datum

Sampling line

150m

50m

200m

250m

832

C1

Trafficlanes

Centralreservation

610 7105

610

C2

350m

4+8x

(No.

Inte

rvie

wer

s)

30m

830.1

831

831

1600m563

562

7202

800m563

562

7208

400m

7202

7208

600m

7202

7208

P

1200m

584

584.1

670

670

See Note 1

670 See Note 2

P

C1

830.1

650m

See Note 3

November 2009A4/12



Plan Sv4: Traffic survey on a two-lane dual carriageway road with a permanent speed limit of 50 or 60 mph

Notes:





November 2009 A4/13



Plan Sv5: Traffic survey on a two-lane dual carriageway road for which the national speed limit applies

3.0

Datum

Sampling line

150m

50m

C1

Trafficlanes

Centralreservation

610 7105

610

B

4+8x

(No.

Inte

rvie

wer

s)

30m

400m

P

C1

831

831

7202

200m

7202

7208

7208

832

600m

7202

7208

800m

7202

7208

2400m

3200m

584

584.1

562

563

1200m584.1

584

1600m563

562

250m

350m

830.1

671

P

670 See Note 1

670 See Note 2

830.1

850m

See Note 3

November 2009A4/14



Plan Sv5: Traffic survey on a two-lane dual carriageway road for which the national speed limit applies

Notes:

1. At survey sites on dual carriageways subject to the national speed limit, a temporary mandatory speed limit of 40mph is recommended.



4. For safety reasons, the siting distance of the first sign should be beyond the anticipated end of the queue. For example, a ‘hazard’ sign (562) with supplementary plate ‘Census 3 miles’ (563) may be required. The location of the end of the queue should be monitored and additional signs should be added if necessary.

November 2009 A4/15



Plan Sv6: Traffic survey on a three-lane dual carriageway road for which the national speed limit applies – interviewing from the nearside

610 831

C1

610 7105

830.1

831

C1

Datum

300m

50m

400m

500m

Trafficlanes

Centralreservation

C1

830.1

Sampling line

3.0

B

832

4+8x

(No.

Inte

rvie

wer

s)

200m

7202

7208

400m 7208

7202

600m 7208

7202

800m 7208

7202

675m

30m830.1

725m

610

P

C1

610 7105

P

3200m

1200m584.1

584

1600m563

562

2400m

584

584.1

562

563

670

670

See Note 1

See Note 2

671

850m

See Note 3

November 2009A4/16



Plan Sv6: Traffic survey on a three-lane dual carriageway road for which the national speed limit applies – interviewing from the nearside

Notes:




4. For safety reasons, the siting distance of the first sign should be beyond the anticipated end of the queue. For example, a ‘hazard’ sign (562) with supplementary plate ‘Census 3 miles’ (563) may be required. The location of the end of the queue should be monitored and additional signs should be added if necessary.

November 2009 A4/17



Plan Sv7: Traffic survey on a dual carriageway entry slip road - lane closure at the downstream end of the slip road

C1

6107105

610

7202

7208

C2

200m

50m

150m

A

Datum

670

80m 831

7202

7208

25m 831

150m

830.1

Sampling line

P

832Datum

4+8x

(No.

Inte

rvie

wer

s)

230m

3.0

562

563

Trafficlanes

P

584.1

584

130m

115m

100m

45m671

Hardshoulder

See Note 1

See Note 3

November 2009A4/18



Plan Sv7: Traffic survey on a dual carriageway entry slip road - lane closure at the downstream end of the slip road

Notes:


2. Depending on the length of the slip road, speed limit repeater signs may be required. For the spacing of these repeater signs, see Chapter 8, Part 1: Design, Table 3.4, Note 1.


4. The distance shown on the sub-plate to diagram 563 should be that to the first traffic cone.

5. For safety reasons, the siting distance of the first sign should be beyond the anticipated end of the queue. The location of the end of the queue should be monitored and additional signs should be added on the slip road, and at the junction, as necessary.

November 2009 A4/19


Annex 5 example Traffic Count and Interview Forms

ANNeX 5 eXAmPle TRAFFIC CouNT AND INTeRvIeW FoRmS

54

ANNEX 5 EXAMPLE TRAFFIC COUNT AND INTERVIEW FORMS These forms are to be used as a guide, final form questions and layouts to reflect local circumstances and the needs of the survey, with classification, origin, destination and journey purpose as a minimum.

RoadName/Location……………………………………………………………………………… Interview Direction Yes 1 No2 Travel Direction ……………………bound

Date Site No. Lane No. 1/2 Hr Starting Enumerator No.

0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

1. Car 25 50 75 100 125 150 175 200 225 250

2. London Taxi 25

3. Other Taxi/Minicab 25 50

4. Motorcycle /Scooter 25

5. Pedal Cycle 25

6. Van (car based) 25 50

75

7. Van (4 tyres) 25 50

8. Light Goods Vehicle 25 (6 tyres no plate) 50

9. Medium Goods Vehicle 25

(6 tyres with plate) 50

10. HGV (3 axles) 25 50

11. Large HGV 25 (4+ axles) 50

75

12. Public Service Bus 25 50

13. Coach or Private Bus 25

14. Minibus 25

15. Other 25

Logo and

Company Name

LONDON & SOUTH EAST ENGLAND TRAVEL SURVEY

November 2009 A5/1

Novem

ber 2009

volume 5 Section 1

Part 4 TA 11/09

e postcode?”

”hat you are carrying?

Vehicle Type:1. Car2. London Taxi3. Other Taxi/Minicab4. Motorcycle/Scooter5. Pedal Cycle6. Van (car based)7. Van (4 tyres)8. Light Goods Vehicle (6 tyres, no plate)9. Medium Goods (2 axles)10. Heavy Goods Vehicle (3 + axles)11. Coach or Private Bus12. Minibus

Purpose:1. Home2. Usual Workplace3. Collect/Deliver Goods4. Other Work/Emp. Business5. Shopping/Use Services6. Sport / Entertainment/Social7. Education8. Hotel / Holiday Home9. Escort - Work10.Escort - Education11.Escort - Other

Site Number Lane Number Interviewer Number Serial NumberTime Period

0

Origin 2

LONDON & SOUTH EAST ENGLAND TRAVEL SURVEY

e postcode?”


Origin 2

e postcode?”


Origin 2

Load:1. Agriculture, unprocessed food2. Chemicals, rubber,

plastic3. Coal, ores, petrol4. Processed food, drink,

tobacco5. Metals, metal products6. Transport equipment7. Other mineral products8. Textiles, papers, glass9. Machinery, electronic10.Mail, parcels11.Tools etc (service vehicle)12.Unknown13.Empty

A5/2

Annex 5

exam

ple Traffic Count and Interview

Forms

55

OriginPurpose

Screen1

If vehicletype 6

If purpose is 3not Destination 1

Ifpurpose is

3

DESTINATION: FULL POSTAL ADDRESS“Can you give me the address of your next stop”

ORIGIN: FULL POSTAL ADDRESS“Can you give me the address of your last stop”

“What is your hom

Vehicle type 1-5

Vehicle types 7-10“Can you tell me w

Other

“Have you just got off a train?” Y N“Are you going to take a train?” Y N

To Station: From Station:

Postcode Postcode

Property, street & number and locality as appropriate:

Town/County

Logo and Company Name

VehicleType

Dest.Purpose

Screen2

VehicleOccu-pancy

IncludeDriver

1

Yes 1

No 2

DK 3

Yes 1

No 2

DK 3


Town/County

OriginPurpose

Screen1

If vehicletype 6

If purpose is 3not Destination 1

Ifpurpose is

3

DESTINATION: FULL POSTAL ADDRESS“Can you give me the address of your next stop”

ORIGIN: FULL POSTAL ADDRESS“Can you give me the address of your last stop”

“What is your hom

Vehicle type 1-5


Other



Postcode Postcode


Town/County

VehicleType

Dest.Purpose

Screen2

VehicleOccu-pancy

IncludeDriver

2

Yes 1

No 2

DK 3

Yes 1

No 2

DK 3


Town/County

OriginPurpose

Screen1

If vehicletype 6

If purpose is 3not

Destination 1

Ifpurpose is

3

DESTINATION: FULL POSTAL ADDRESS“Can you give the address of your next stop”

ORIGIN: FULL POSTAL ADDRESS“Can you give the address of your last stop”

“What is your hom

Vehicle type 1-5Home Purpose


Other



Postcode Postcode


Town/County

VehicleType

Dest.Purpose

Screen2

VehicleOccu-pancy

IncludeDriver

3

Yes 1

No 2

DK 3

Yes 1

No 2

DK 3


Town/County

Home Purpose

Home Purpose


Annex 6 example leaflet

ANNeX 6 eXAmPle leAFleT

TRAvel SuRveYS IN THe SouTH eAST ReGIoN oF eNGlAND

Transport for London and the Highways Agency are jointly carrying out a major programme of roadside traffic surveys in the south-east region of England. The information from these surveys will be used to develop and plan future investment in the transport system. Stopping vehicles and asking drivers about their journeys is the only effective way of obtaining the required information and the Highways Agency, as Data Controller, would be grateful for your assistance.

We should emphasise that although drivers are required to obey the instructions of the police officer, participation in this one-day survey is purely voluntary. All information is collected on a strictly confidential basis.

Address information is required to enable an accurate geographical location to be allocated when details of journeys are analysed. Once this has been done the addresses and survey questionnaires will be destroyed.

If you would like more information about the survey, please ring the survey Helpline on [insert telephone number] where you can speak to a representative of the Data Controller.

Finally, we would like to apologise for any inconvenience caused by the survey and thank you for your co-operation. Every effort has been made to minimise delays and disruption to traffic.

Data collection by [insert name of Company] for the Highways Agency

Leaflets should cover why and how recipients have been selected, the purpose of the RSI and how it assists the study and its objectives. It should also cover how to seek further information and ways to complain.

November 2009 A6/1


eSTIoN

Annex 7 managing Congestion

ANNeX 7 mANAGING CoNG

A7.1 Congestion is more likely to occur during peak periods at Stop/Go sites and sites involving lane closures on dual carriageways. Where congestion is likely to be an issue, the survey design should reflect this, either in reducing the number of questions, using electronic data entry methods, altering the layout of the site, changing the sample rate or considering a different survey method such as self completion postcard surveys.

Stop/Go Sites

A7.2 Interviewing can be suspended easily and therefore levels of congestion can potentially be controlled by interviewing ‘little and often’. If queues start to build up rapidly the situation may arise where suspensions become the rule and sample rates drop well below desired levels.

A7.3 To maintain sample rates, queues should be kept as short as possible even when congestion is not a serious problem; allow traffic to be released when queues exceed a predetermined limit or block significant junctions; and distribute reply paid postcard questionnaires intermittently if it becomes difficult to achieve sufficient face-to-face interviews.

Dual-Carriageway Sites

A7.4 On short dual carriageway sections it may be possible to open closed lanes for short periods to allow traffic to flow. To avoid a lane closure during peak periods it may be possible to issue postcards and then revert to a lane closure with face-to-face interviews when traffic conditions allow. However, removing and reinstating extensive traffic management may be difficult and time consuming.

Sites on motorway Slip Roads

A7.5 Surveys on motorway entry slip roads are generally carried out successfully without any major problems. However, if the motorway mainline becomes congested, queues can tail back through the site, causing delays on the local highway network. Under these circumstances it is recommended that the site should be temporarily suspended until congestion eases on the mainline. This allows queues to dissipate more quickly and helps to maintain the co-operation of the travelling public.

Tem

A7shocovposwitpre081

November 2009

porary Suspensions

.6 When considering temporary suspensions, efforts uld be made to secure sufficient representative er within the peak periods. For example, if it is not sible to survey the morning peak period throughout hout causing excessive delays, then it may be ferable to cover the periods 0600 to 0730 and 5 to 0900 hours rather than 0600 to 0800 hours.

A7/1


Annex 8 Sampling

ANNeX 8 SAmPlING

A8.1 A critical assumption, in this example, is estimating the percentage of vehicles using a particular road which are going to a specific destination (i.e., a single zone). The authority has taken a 16-hour manual classified count of 30,000 vehicles per day and estimates, from local knowledge, that it is unlikely that more than 20% of the traffic will be going to the destination of interest. The authority wishes to know for example:

Either a) within a band of 10% i.e. +/- 5% or b) within a band of 4% i.e. +/- 2%

What proportion of traffic is, in fact, going to the destination?

A8.2 What proportion of the traffic will need to be interviewed? The general formula for determining the sample size ‘q’ is:

P(1-P)Q3

(E/1.96)2(Q-1) + P(1-P)Q2

where: Q = total traffic flow E = acceptable error or accuracy (expressed as a number of vehicles) P = proportion above which it is unlikely that the proportion of flow which is of interest falls.

In the above example:

Q = 30,000 P = 0.20

For case a) E = 1,500 (i.e. 5% of 30,000) For case b) E = 600 (i.e. 2% of 30,000)

Therefore, for case a), the required sample ‘q’ is given by:

0.20 (1 - 0.20) 30,0003

(1,500/1.96)2 (30,000 - 1) + 0.20 (1 - 0.20) 30,0002

= 244 interviews required (about 1% of the total flow)

November 2009

and for case b), q is:

0.20 (1-0.20) 30,0003

(600/1.96)2 (30,000 - 1) + 0.20 (1 - 0.20) 30,0002

= 1,462 interviews required (about 5% of the total flow)

A8.3 In addition to wanting to know something about traffic going to the first destination as above, the authority may wish to know something about the proportion of traffic going to a second destination. The calculation needs to be repeated with the new estimate of traffic substituted in the formula. If it is considered unlikely that the proportion of traffic going to the second destination is more than 10% and the authority wish to know within a band of 10% i.e. +/-5%, what the actual proportion is, then given Q = 30,000, P=0.10 and E=1,500 (5% of 30,000) then the required sample ‘q’ is given by:

10(1 - 0.10) 30,0003

(1,500/1.96)2 (30,000 - 1) + 0.10 (1 - 0.10) 30,0002

= 138 interviews.

A8.4 If the authority wishes to estimate for both destinations to within +/-5% then 138 interviews are needed for the second destination and 244 interviews for the first. In this case 244 interviews would be carried out, giving the estimate for the second destination to a greater accuracy than is required.

A8.5 When data is being collected for a large multi-zoned modal, it is impossible to calculate this for every O-D pair for each RSI site as the origins and destinations are not yet known. Once a survey site has been established it is best practice to collect as much data as reasonably practical.

A8/1

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