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Dept. of Civil Engineering

Course No: CE 452

TRANSPORTATION

ENGINEERING SESSIONAL -II

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Course Instructor: Mr. Minhazul Islam

Khan (Lecturer)

Ms. Nuzhat (Lecturer)

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Presentation on

Traffic Volume Study

Presented by4th Year 2nd Semester

Section; B

Group No: 4

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Name Student ID

Wasi Uddin Ahmed 11.01.03.129

Shahana Akter Esha 11.01.03.073

Farjana Rahman Tripty 11.01.03.077

Suhana Sultana 11.01.03.095

Antora Dhali 11.01.03.114

Shajeda Allam Mahbuba 10.01.03.103

Sazzad Hussain 10.01.03.152

Tuhin Hasan 10.01.03.156

Study Area (Panthapath) on

Google Earth

Mirpur

Road

Russel

Square

Panthapath-

Green Road

Intersection

Green Road

SAARC

Fountain

Green Road

Mirpur

Road

Kazi Nazrul

Islam Road

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Presentation Contents

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Introduction General Objectives of Traffic Volume Study Methodology Survey procedure Data Collection Analysis of collected data Conclusion Recommendations Limitations of the Study

OBJECTIVES

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Design purposes•Structural and geometric design

• Intersection design

• Design of side walks, pedestrian crossing etc.

Improvement purposes•Allocation of limited maintenance budget rationally

• Improvement of roadway operating condition

Planning purposes• Planning of road maintenance and improvement policies

• Deciding if there is need for improvement or expansion

Other purposes• Dynamic traffic management

• Estimation of highway use

• Measurement of current demand of a facility

• Economic feasibility evaluation

• Computation of accident rates

Data Collection

Location: Panthapath Road Segment between Russell

Square and Green road-Panthapath Intersection

Date: 27.11.2014

Day: Thursday

Time: 9:00 a.m. – 09:30 a.m.

Weather condition: Hazy & Clear

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Objectives of the Study

Determination of Vehicle Composition of traffic

stream

Determination of Service Flow Rate

Determination of Directional Distribution (DD)

Estimation of ADT based on expansion factors

Drawing Flow-fluctuation curve

Methods of Counting

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Manual Counting Methods

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Automatic Counting Methods

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Selected Method

Manual Method using hand tally and manual counters

Reasons:

Simple and Direct

Classified vehicle count can be obtained

Data can be used immediately after

collection

No special equipment required

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Survey Procedure

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Analysis of

Collected Data

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Determination of Vehicle

Composition of Traffic streamImportance of Vehicle Composition

• Affects the road capacity

• Influences decisions like type of improvement, maintenance and

traffic control devices to be used

Vehicle Classification Observation in 30 Minutes

Bus 5

CNG Auto Rickshaw 145

Jeep, Microbus, Ambulance 254

Motorcycle 145

NMV 225

Utility 19

Truck 0

Car 265

Total 858

Vehicle Composition of Traffic

Stream

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Bus1%

CNG Auto Rickshaw14%

Jeep, Microbus, Ambulance24%

Motorcycle14%

NMV20%

Utility2%

Truck0%

Car25%

Vehicle Composition %

Bus CNG Auto Rickshaw Jeep, Microbus, Ambulance Motorcycle NMV Utility Truck Car

Car & Jeep, Microbus, Ambulance are the dominant vehicles. The 2nd

dominant vehicle class is NMV.

Truck wasn’t available at that time of the day.

Definitions

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Flow Rate

The equivalent hourly rate at which vehicles pass over a given point or section

of a lane or roadway during a given time interval less than 1 hour usually 15

minutes

Service Flow Rate

The maximum hourly rate of a roadway section during a given period under

prevailing roadway condition

Importance of Flow Rate

A short duration count (for e.g. 15 minutes count) can be converted into an

equivalent hourly rate

Determination of Service Flow Rate

in PCU/PCE unit

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Vehicle Classification Observation in

30 Minutes

PCU

Factor

Total vehicle

(PCU/30 min)

Service flow rate

(PCU/hr)

Bus 5 3 15 30

CNG 145 0.5 72.5 145

Car 265 1 265 530

Jeep, Microbus, Ambulance 254 1.5 381 762

Motorcycle(MC) 145 0.25 36.25 72.5

NMV 225 0.5 112.5 225

Utility 19 1.5 28.5 57

Truck 0 2 0 0

Total 1822

Hence, flow rate for 9:00a.m.-09:30a.m. is 1822 PCU/hr (Group 04)

Average Daily Traffic (ADT) and Annual

Average Daily Traffic (AADT)

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ADT:

The volume during a given time period (in the whole days greater than one but less than one year) divided

by the number of days in the time period.

Importance of ADT• Mainly useful for determining the Annual Average Daily Traffic (AADT) which is

the standard measurement for vehicle traffic load on a section of road

• AADT is used for determining funding for the maintenance and improvement of

highways

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ADT:

Estimate 24-hr volm using the hourly expression factor for East to

West:

= ((1346*18.80) + (1405*17.11) + (1546*18.52))/3 = 25992

Total weekly volm = 25992*7.012 = 182257

ADT = 182382/7 = 26037

Estimate 24-hr volm using the hourly expression factor for West to

East:

= ((1822*18.80) + (1672*17.11) + (1682*18.52))/3 = 31338

Total weekly volm = 31338*7.012 = 219742

ADT = 219742/7 = 31392

AADT:

AADT = (26037+31392)*1.756 = 100845

Determination of Directional

Distribution (DD)

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Directional Distribution

Shows the ratio of traffic on opposite sides of the road during the peak or design

hour, commonly expressed as percent in the peak and off-peak flow directions.

Importance of Directional Distribution

•Accounts for the directional distribution of traffic

• Used to convert average daily traffic to directional peak hour traffic

Direction Time PCU/hr Average

PCU/hr

Directional

distribution

(%)

East to West

(Panthopath to

Russell

square)

9.00-9.30 1346

1432 4510.30-11.00 1405

11.00-11.30 1546

West to East

(Russell

square to

Panthopath)

9.00-9.30 1822

1725 5510.30-11.00 1672

11.00-11.30 1682

45%

55%

DIRECTIONAL DISTRIBUTION

East to West West to East

Flow-fluctuation Curves

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Flow-fluctuation Curve

Graph of %ADT versus Time usually for a 24 hour period

Importance of Flow-fluctuation Curve

24 hour flow fluctuation curve gives

• Peak Hour Factor (PHF)

• Design Hourly Volume (DHV)

DHV = PHF x ADTTime East to West

flow Rate

(PCU/hr)

West to

East Rate

(PCU/hr)

East to

West flow

Rate ADT

(PCU/day)

West to

East Rate

ADT

(PCU/day)

East to

West flow

Rate %ADT

West to

East Flow

Rate %ADT

9:00 -

9:30 am1346 1822

26037 31392

5.17 5.81

10:30 –

11:00

am1405 1672 5.4 5.32

11:00-

11:30

am1546 1682 5.93 5.36

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1, 5.17

5, 5.4

10, 5.931, 5.81

5, 5.32 10, 5.36

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5.2

5.4

5.6

5.8

6

0 2 4 6 8 10 12

%A

DT

TIME

Chart Title

Flow-fluctuation Curves

1, 1346 5, 140510, 1546

1, 18225, 1672 10, 1682

0

500

1000

1500

2000

0 2 4 6 8 10 12

FL

OW

RA

TE

TIME

Chart Title

Flow Fluctuation Curve (Flow Rate vs Time)

Flow Fluctuation Curve (Flow Rate vs Time)

Conclusions

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• Light vehicles were the most frequent vehicle in the corridor which

comprised of 72% of the total traffic volume and least frequent vehicles were

buses comprising only 1% of the total traffic volume.

• The service flow rate obtained for our Group was 1822 PCU/hour.

• The directional distribution in the corridor was 55-45 showing that the

traffic scenario of the site is quite unstable and unplanned.

• The Average Daily Traffic (ADT) for the W-E direction of the road is 31392

vehicles which is a rather low estimation of such a busy street.

• The flow fluctuation curves obtained for both the sides of the road were

rather straight instead of showing profound peaks

Limitations and Recommendations

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Direct Manual method being less accurate, indirect method using

video recorders should be used for future surveys.

More representative results of service flow rate would be obtained if

24 hours volume is counted and the flow-fluctuation curve would

show two distinct peaks around morning and evening rush hours.

Expansion factors used for the calculation of ADT were developed for

a rural primary road.

Proper enforcement of traffic regulations in the study corridor must

be ensured.

If future surveyors collect data for 24 hours and for 3 days they will

get much more representative results than those obtained in this study.

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References

Mr. Mudasser Seraj Rafi, Technical Report of Volume Study on A Collector Road

Traffic Volume Counts. Retrieved from:

www.ctre.iastate.edu/pubs/traffichandbook/3trafficcounts.pdf

Volume study. Retrieved from:

http://www.learningace.com/doc/5860600/7f7ee6e961409475037f6cf670aacb85/12_volume-study

V. Thamizharasan and K. Krishnamurthy, Study of the effect of traffic volume and road width on

PCU value of vehicles using microscopic simulation

Kirsten Duivenvoorden, The relationship between traffic volume and road safety on the secondary

road network, www.swov.nl/rapport/D-2010-02.pdf

Roads Department. Ministry of Works and Transport. Roads Department. Private Bag 0026.

Gaborone, Botswana: Traffic Data Collection and Analysis,

www.vegvesen.no/_attachment/61658/binary/14468

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Thank You