magesa siraji-final (2)

7/30/2019 Magesa Siraji-final (2)

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PROJECT TITLE: DESIGN OF TRAFFIC

CONTROL DEVICES

CASE STUDY: JUNCTION OF NELSON

MANDELA-TAIFA ROAD

STUDENT NAME: SIRAJI MAGESA

ADM NO: O90101P6232


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Junction of Nelson Mandela-Taifa roadis located at Mibulani ward in Temeke

municipality Dar -es- Salaam city. This

junction is non signalized and the type

of junction is inform of T-junction. The

points of conflicts at an intersection can

be further reduced by the use of traffic

control devices. There fore will facilitatemovements through the junction(T-

junction) towards Nelson Mandela

which connects Ubungo and Taifa road.

INTRODUCTION


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PROBLEM STATEMENT

Due to conflicts of traffic at junction, the following

problems has become a critical issue.

There are increase in accidents and traffic congestion

especially during working days or working hours.These lead to delays and also lose of lives and

properties.


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PROJECT OBJECTIVES

MAIN OBJECTIVE

To design pre-timed traffic signal.

SPECIFIC OBJECTIVES

To design traffic control devices

To determine types of junction

To perfom traffic counting

To draw geometric dimension


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In order to achieve this project I had to do site

visit, literature review, data collection, traffic

counting and data analysis as the core

methodology of this project.The method which I used to collect data is the in-

person observation

METHODOLOGY


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SIGNIFICANCE OF THE PROJECT

If traffic control devices will be designed, weare expect to reduce the number of accidents

and traffic congestion especially during

working days.


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LITERATURE REVIEW

INTRODUCTION

An intersection is the area where two ormore street join or cross at grade. At

intersection where there are a large number of

crossing and turning traffic, there is possibility of

several accidents as there non orderly

movement thus to say there cross stream of atraffic flow separate.


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TRAFFIC CONTROL DEVICES

Are the management measure which are used in

variety ways to control traffic movement both vehicles

and pedestrian at the intersection.

Traffic control devices, these are devices which used toimprove the overall traffic conditions in the most

convenient, safe and economic way. For example,

traffic signals permit the vehicles and pedestrian to

cross in proper manner by controlling conflicts, speedcontrols, control drives from over speeding.


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REQUIMENTS OF TRAFFIC CONTROL DEVICES

The installation of these devices should be muchthat draw the attention of the users. Attention

depends upon the location size, colours etc.They

should be placed within the cone of clear vision

of road used.Fulfill the need or functionalrequirement


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BASIC REQUIREMENT OF TRAFFIC SIGNAL

The traffic signal shall be effective if the followingrequirement are taken

ATTENTION

The signal must attract the attention its user, and the

factor that affect the attention arePosition of placing the signal.

Height and type of mounting

Design of signal head and face

Power of the bulb[usually 40-100w]

MEANING

Each indication of signal should convey one and only onemeaning clearly without any scope of misinterpretation.


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THREE TYPES OF SIGNS, GIVING

ORDER, WARNING OR INFORMATION

1.Regulatory(mandatory),These signs inform theroad users about prevailing laws and regulations.forexamples no parking

2.Warning (cautionary) sign,These signs warn theroad users about the existence of certain hazardousconditions. For example pedestrian crossing3.Informatory.(guinding)signs. These signs are for

information and guindance of road users and callattention to thing which might be of interest tothem. For example direction indicators'.


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TYPES OF JUNCTION

The following are types of junctions as

mentioned below.

1.T-junction2.Acute junction

3.Square junction and etc.


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TYPES OF TRAFFIC CONTROL DEVICES

The following are types of traffic control devices

1.Traffic island

2.Traffic signals

3.Pavement marking

4.Traffic sign


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1.Traffic island

Is the types of control device which improve the efficiency

of operation at junction,also reduce the area of trafficconflicts

Classification of traffic island

Islands are usually classified according to the purpose for

which they are used as shown below1.Channelising islands

This used to separate control or direct the movement of

traffic streams.

2.Round about

A central islands of circular, elliptical or other shape located

in the centre of an intersection used for channelization.


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3.Divisional island

The y used to provide on four or more lane highway to

segregate the opposing traffic and etc.

2.TRAFFIC SIGNALS

Guide the road users and provide information. Also give

warning about abnormal driving conditions ahead.

Types of signals.1.pre- timed (fixed time)signal

They sequence in which the signals redred, yellow-green-

yellow as they appear on each approach of junctions is

fixed and repeated after a fixed interval in seconds.


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2.Vehicle actuated signalsThese signals change the length of green signal inter val,

in accordance with the actual traffic volume on the

particular approach of the junction.

3.Pedestrian actuated signalsSignals are sometimes provide on busy urban streets for

crossing of the pedestrians, they temporarily show a red

light for the traffic to stop.


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PHASING

Is the procedure by which the traffic streams

are separated, the number of phase required

for proper and efficient operation of signalized

intersection varies with the composition anddirection of traffic flow.


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TRAFFIC COUNTING

Is the process of counting the vehicles and pedestrianwhen crossing to the road intersection.

TWO METHODS OF TRAFFIC COUNTING1:Manual method, use to observe to count and classifytraffic flowing past a fixed point person can use a fieldto suit the particular requirement of any intersection.2:Automatic method, this count method provides a

means for gathering large amount of traffic data,usually taken in interval for each 24hrs period.


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DATA COLLECTION

Is the process of collecting data, the data arecollected in two ways, person observation andsecondary participation.

The following are data which collected in orderto accomplish my project

1:Traffic counting and the method which used tocount is the manual counting for 7days in 12hrseach day.

2:Traffic accidents

3:Geometric dimension.

RESULTS OF DATA COLLECTION FOR TRAFFIC


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VEHICLE

TYPE

MON

6AM-6PM

TUES

6AM-6PM

WED

6AM-6PM

THIR

6AM-6PM

FRIDAY

6AM-6PM

SAT

6AM-6PM

Sun

6AM-6PM

TOTAL

CARS 9900 7712 7823 7820 7921 7893 2400 51469

PICKUP 5921 5200 5000 5300 5320 4300 819 31860

LORRIES

UNDER 5T

800 804 812 923 823 734 571 5467

LORRIESOVER 5T

700 712 730 750 800 760 512 4964

SEMITRAIL

ERS

160 150 140 151 145 160 100 1006

LORRIES

WITH

TRAILERS

150 152 145 160 147 145 135 1034

BUS

UNDER25SEAT

850 800 812 840 820 720 520 5362

BUS OVER

25SEAT

700 712 705 706 650 680 350 4503

OTHER

VEHICLES

- - - - - - - -

TOTAL 19181 16242 16167 16650 16626 15392 5407

RESULTS OF DATA COLLECTION FOR TRAFFIC

COUNTING FOR 7DAYS.

d d d d h


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MONTH 2007 2008 2009 2010 2011 2012

JAN 0 1 1 1 2 1

FEB 1 1 1 1 1 3

MAR 1 1 0 1 0 2

APR 0 2 1 2 1 1

MAY 1 1 2 1 2 0

JUN 2 1 1 1 2 1

JULY 0 1 0 2 1 1

AUG 1 0 1 0 1 0

SEP 0 0 2 0 1 1

OCT 1 1 2 1 0 1

NOV 1 1 0 0 2 3

DEC 0 0 0 0 0 0

TOTAL 08 10 11 10 13 14

Accident data recorded at the junction

from Temeke police station

verage ra c vo ume ow n o pcu ve c e r


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verage ra c vo ume ow n o pcu ve c e rat the junction.

Appr.from

Mbagala Ubungo K/koo Total

Right Strait Left Strait Right Left

Mon

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400 550 200 400 266 200 2016

Tues28/12

380 440 210 300 180 256 1766

Wed

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400 430 250 250 200 231 1761

Thur

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470 400 300 310 200 136 1816

Frid

31/12

400 320 350 340 100 291 1801

Sat

02/01

360 491 290 230 150 159 1680

Sun03/01

100 190 110 130 83 100 713


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DATA ANALYSIS:

Traffic counting

.The maximum traffic flow/peak day entering the intersection

from each approach is experienced on the first day (Monday)where traffic volume flow as 950+600+466 from Mbagala,Ubungo and K/koo respectively refer table 3

Average traffic volume flow =(950+600+466)/3

There fore =672vehicle/hr

From the minimum vehicular volume warrant this specifies thatthe average traffic volume flow for 8hrs on both approachshould be at least 650motor vehicles per hr on major streetswith single lane and 800vehicle on streets with two or morelanes

So the results shows that the average exceeds the specifiedwarrant hence installation of traffic signal at this intersectionis required.


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CONVERSION OF TRAFFIC VOLUME INTO PCU PCU is the single unit used to convert all the vehicles

into single unit. Since traffic counting obtaining different types and

classes of this traffic should be converted to a single

unit.


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ACCIDENT DATA RECORDED

It is shown that the above table of accident at the intersection areincreasing gradually from one year to another i.e in 2007, theaccident recorded was 8 but in 2009 the accident fall to10 and from2010 -11, the accident recorded was increasing.

The annual growth rate of the accident is calculated from the followinformula

ANNUAL ACCIDENT GROWTH={(Y1/Y)-1}*1/n

Where y is the no. of initial accident

Y1 is the no. of final accident

n is the no. of year

There fore ={(14/8)-1}*1/6

0.125=13%From the accident, experience warrant which specifies that where 5 or

more accidents have occurred within 12months period, then thetraffic control signal is needed.


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CONFLICT AT THE INTERSECTION AND ITS DIMENSION


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REFERENCES

Kadiyali, L. (1989). Principles and practice of

highway engineering. Delhi: Khanna tech.

publications.

Kelly, W.(1987).Fundamental of traffic

engineering.

Vaziran, V. (1988). Transportation traffic

engineering. Delhi: Khanna publisher

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