A STUDY ON THE CAUSES OF TRAFFIC CONGESTION IN

CHITTAGONG CITY: GATE NO.2, GEC AND NEW MARKET

INTERSECTIONS IN THE PERSPECTIVE

Sazia Ferdous Nitu1* ,M. Mahsin1*,

1 Undergraduate Student, Department of Civil Engineering, Southern University Bangladesh,

Chittagong, <nitusazia24@gmail.com> 2 Lecturer, Department of Civil Engineering, Southern University Bangladesh, Chittagong,

<hasancuet90@gmail.com>

*Corresponding Author

ABSTRACT

One of the most challenging and complicated issues in city management in the present decade for

Bangladesh is the traffic problem. It is a very common phenomenon in almost all the cities of

Bangladesh. Presently, traffic congestion problem in Bangladesh are increasing at an alarming rate. The

traffic problem has become to a very dangerous aspect and has already implicit agonizing extent in the

cities of Bangladesh. Traffic management in Chittagong is not well organized as Dhaka so that the

problem is becoming more complicated as the number of people in Chittagong is increasing and it is

getting the priority after Dhaka. This article is dedicated to determine the current condition of traffic

management in Chittagong City. This study explores the causes involved in traffic congestion including

heavy concentration of vehicles, inadequate road infrastructure, faulty signaling equipment and poor

enforcement of traffic with respect to the three intersections (Gate No. 2, New Market and GEC

intersections). At the end of the paper the researchers tried to identify the solution of traffic jam in

Chittagong Metropolitan City.

Keywords: Traffic Congestion, Rotary intersection, PCU, Traffic Volume, Heavy vehicle.

INTRODUCTION

Traffic congestion is a common phenomenon in almost all the cities of Bangladesh. The situation has

got to a critical stage and has already encountered unbearable proportions in the cities of Bangladesh.

(K.D.A. 2001)[1]. Thus it is important in understanding the underlying issues in regarding the urban

problems like traffic jams which has become an area of interest by both academicians and practitioners.

As such, the current study is an attempt to explore the causes and solution of traffic jam in Chittagong,

the commercial capital of Bangladesh [2]. Therefore, it is a commensurations step for us to conduct this

study which would help us to identify problems and solutions for traffic congestion for busy

intersections that symbolizes the overall scenario of the port city.

METHODOLOGY

To meet the motive of this study, various methodologies were used which are discussed briefly.

Traffic jam study is the collection and analysis of measurable factual data relating to traffic. Traffic

volume counts can be carried out manually or by automatic counters, by moving observer method

(Highway Engineering, Gusto & Khanna). Geometric survey is done by Total Station Instrument.

Traffic volume study: Traffic volume is defined as the number of vehicles that passes a point along a

road way or traffic lane per unit time. A measure of traffic flow, volume is commonly measured in units

of vehicle per day, vehicle per hour, vehicles per minute, and so on. By using Passenger Car Unit (PCU)

method we get the following equation[4]:

1st International Conference on Research and Innovation in Civil Engineering (ICRICE 2018), 12 –13 January, 2018, Southern University Bangladesh (SUB), Chittagong, Bangladesh ISBN: 978-984-34-3576-7

Qp = 280w (1+e/w) (1-p/3)

(1+w/l)

Qp= Passenger car unit, PCU per hour

w= Width in weaving section in meter (6-18)m

eav= Average entry width in meter. eav = (e1+e2)/2

l= Length of weaving section between the end of island in meter.

p= Proportion of weaving traffic, p = b+c

a+b+c+d

a= Left turning traffic moving along left extreme lane

d= Right turning traffic moving along right extreme lane

b= Crossing/weaving traffic turning towards right while entering the rotary

c= Crossing/weaving traffic turning towards left while entering the rotary

Fig- 1: Rotary Intersection & showing the study area which includes the three intersections highlighted

in blue

INVESTIGATION RESULT AND CALCULATION: PCU CALCULATION for 2 No. Gate (Morning). 1hr

Table-1 Fig: 1- Traffic Flow for 2 No. Gate

(Morning)

Approach Left Turning Straight Ahead Right Turning

North 655 932 1477

South 760 661 206

East 834 2266 412

West 2314 2242 455

Traffic flow at 2No. Gate Intersection

1st International Conference on Research and Innovation in Civil Engineering (ICRICE 2018), 12 –13 January, 2018, Southern University Bangladesh (SUB), Chittagong, Bangladesh ISBN: 978-984-34-3576-7

PCU CALCULATION

GEC Intersection; Time: 1hr

Table-2 Fig: 2-Traffic flow in GEC Intersection

PCU CALCULATION

New Market Intersection- Morning/Evening Time: 1hr

Table -3 Fig;3- Traffic flow for New Market Intersection

Investigation Result

2 No. Gate Intersection Peak Traffic Flow Morning Time Maximum Traffic Flow West direction (9511 PCU/hr) Maximum Flow in one direction 5011 PCU/hr

Weaving width at the rotary. W w=31m (not appropriate according to the

condition and should be revised) e/w 0.83

w/l 0.53 (not appropriate according to the

condition and should be revised) P 0.6 Qp (Theoretical Capacity) 6273 PCU/hr Remarks Intersection Needs to be revised.

Table:4- Illustration of Present Traffic in 2 No. Gate Intersection

GEC Intersection Peak Traffic Flow Evening Time

Maximum Traffic Flow South (6621 PCU/hr)

Maximum Flow in one direction 3646 PCU/hr

Weaving width at the rotary. W w=15.85m

e/w 0.557

w/l 0.247

P 0.73

Qp 4190 PCU/hr

Approach Left Turning Straight Ahead Right Turning

North 991 1859 0

South 0 2382 599

East 4566 0 337

West 927 406 1215

Traffic flow at GEC Intersection

Approach Left Turning Straight Ahead Right Turning

North 1756 521 1577

South 892 1472 363

East 484 656 375

West 2368 453 944

Traffic flow at New Market Intersection

1st International Conference on Research and Innovation in Civil Engineering (ICRICE 2018), 12 –13 January, 2018, Southern University Bangladesh (SUB), Chittagong, Bangladesh ISBN: 978-984-34-3576-7

Remarks Intersection Needs to be revised.

Table 5: Illustration of Present Traffic in GEC Intersection

New Market Intersection

Peak Traffic Flow Evening Time

Maximum Traffic Flow North (8069 PCU/hr)

Maximum Flow in one direction 4215 PCU/hr

Weaving width at the rotary. W w=15.85m

e/w 0.7

w/l 0.384

p 0.55

Qp 4470 PCU/hr

Remarks Intersection Needs to be revised.

Table 6: Illustration of Present Traffic in New Market Intersection

An independent survey was done to find out the causes of traffic congestions in the three intersection

Fig 4: Survey results for the analysis of causes of Traffic Congestion in 2No. Gate Intersection.

The main causes of traffic congestion in 2No. Gate Intersection were found to be behavioral problem

of drivers, behavioral problem of the pedestrians, no zebra crossings, road design, no speed brakers,

central island diameter and presence of no over bridge as well. The vehicle which was voted for the

root cause of accident was Trucks.

Fig 5: Survey results for the analysis of causes of Traffic Congestion in GEC Intersection.

The main causes of traffic congestion in GEC Intersection were found to be behavioral problem of

drivers as well as behavioral problem of the pedestrians and no zebra crossings. The vehicle which was

voted for the root cause of accident was Private cars.

0%20%40%60%80%

100%120%

Drivers

Pedestrians

Passengers

TrafficPolice

0%20%40%60%80%

100%120%

Drivers

Pedestrians

Passengers

Traffic Police

1st International Conference on Research and Innovation in Civil Engineering (ICRICE 2018), 12 –13 January, 2018, Southern University Bangladesh (SUB), Chittagong, Bangladesh ISBN: 978-984-34-3576-7

Fig 6 : Survey results for the analysis of causes of Traffic Congestion in New Market Intersection.

The main causes of traffic congestion in New Market Intersection were found to be behavioral problem

of drivers as well absence of zebra crossings [5]. The vehicle which was voted for the root cause of

accident was City Service Buses.

Comparison between morning and evening sessions in terms of Traffic volume and Traffic

Capacities for 2 No. Gate Intersection.

Fig -7: Bar chart showing comparison between theoretical traffic volume and practical traffic

volume in terms of morning session for 2 no. gate intersection

Fig -8: Bar chart showing comparison between theoretical traffic volume and practical traffic volume

in terms of evening session for 2 no. gate intersection.

0%20%40%60%80%

100%120%

Drivers

Pedestrians

Passengers

Traffic Police

0

2000

4000

6000

8000

South West West North North East East West

Traf

fic

Vo

lum

e in

PC

U

Direction

Theoretical Traffic Volume inPCU

Practical Traffic Volume in PCU

0

2000

4000

6000

8000

10000

12000

South-West West-North North-East East-South

Axi

s Ti

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Direction

Theoretical traffic volumecapacity

Practical traffic volume

1st International Conference on Research and Innovation in Civil Engineering (ICRICE 2018), 12 –13 January, 2018, Southern University Bangladesh (SUB), Chittagong, Bangladesh ISBN: 978-984-34-3576-7

Fig -9 : Bar chart showing comparison between theoretical traffic volume and practical traffic volume

in terms of morning session for NEW MARKET intersection.

CONCLUSIONS

Traffic volume at evening times has the upper hand in two of three intersections.(GEC and New Market

Intersections).Traffic volume was insufficient in all the directions (Practical traffic volume was way

more than that of Theoretical Traffic Volume).From all the three intersections, it was found that

behavioral problem of drivers was the root cause of traffic congestion.

REFERENCES

1. Asian Business Review, Volume 2, Number 1/2013 (Issue 3) ISSN 2304-2613 (Print): ISSN

2305-8730 (Online)

2. Bangladesh Research Publications Journal (BRP), ISSN: 1998-2003, Volume: 4, Issue: 2, Page

185-197, July August 2010.

3. International Journal of Development and Sustainability Online ISSN: 2168-8662- Volume 1

Number 2 (2012): Pages 476-489 ISDS Article ID: IJDS 1210502

4. S.K. Khanna, Highway Engineering (6th Edition).

5. http://www.distancesfrom.com/bd/directions-from-2-No.-Gate-Bus-Stop-to-Chittagong-New-

Market-Station-Road-via-GEC-Chittagong/DirectionHistory/27123311.aspx

0

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South-West West-North North-East East-South

Traf

fic

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Theoretical traffic volume

Practical traffic volume

1st International Conference on Research and Innovation in Civil Engineering (ICRICE 2018), 12 –13 January, 2018, Southern University Bangladesh (SUB), Chittagong, Bangladesh ISBN: 978-984-34-3576-7