COURSE NO. CE 452GROUP NO : 3SECTION : BYEAR/SEMESTER : 4/2 COURSE TEACHERS:MR. MUDASSER SERAJLECTURER, AUST

AHSANULLAH UNIVERSITY OF SCIENCE & TECHNOLOGY

DEPARTMENT OF CIVIL ENGINEERING TRAFFIC VOLUNE STUDYTRANSPORTATION ENGINEERING SESSIONAL II

Presentation outline

►Definition Objective►

►Scope Methodology Data collection► ►

►Reconnaissance Survey Data analysis Conclusion► ►

►Limitations

Traffic volume study is the procedure to determine mainly the volume of traffic moving on the roads at a particular section during a particular time.

Definition

Definitions(continues)

Service flow rate: The maximum hourly rate of a roadway section during a given period under prevailing roadway condition.

LOS: “Qualitative measures that characterize operational conditions within a traffic stream and their perception by motorists and passengers.” (Highway capacity manual, 1994)

Definitions(continues)

ADT: Average daily traffic is the volume of traffic counted on the roadway(two way) over a given time period (greater than one day but less than one year) divided by the number of days in that time period.AADT: Average annual daily traffic is obtained by adding daily traffic counts over one year divided by 365 days.

Definitions(continues)

Directional Distribution: Directional distribution refers to the percentage of traffic flow in one direction during a particular time of day. This factor is particularly important in the case of commuter roads, where maximum flow occurs in one direction in the morning and the other in the evening. This also needs to be considered for efficient geometric design

Definitions(continues) PCE: PCE means passenger car equivalent to express

various types and characteristics vehicles to a common

type usually the passenger car. One car is considered to one

unit.

Volume/flow: The total number of vehicles that pass over a

given point or section of a lane or roadway during a given

time interval. It may be expressed in terms of annual, daily,

hourly, or sub-hourly periods; usually in vph or vpd.

Volume is an actual number of vehicles observed or

predicted to passing a point during a given interval.

Objectives

The objectives of carrying out traffic volume study are designing, improving traffic system, planning, management etc.

Design purpose: Structural and geometric design of pavements, bridge, and other highway facilities; intersection design including minimum turning path, channelization, flaring, traffic control devices viz. traffic signs, markings, signals based on approach volume and turning proportions etc.

PURPOSES

Improvement purposes: To allocate limited maintenance budget rationally; to improve the roadway operating condition; to examine the existing operating/service condition; to determine the type of improvement measure need to be taken etc.

Planning Purposes: Accurate information on the amount of traffic on the roads is vital for the planning of both road maintenance and improvement policies

PURPOSES(continues)

Dynamic Traffic Management Purposes: Up to date and continuous flow/congestion information is essential for optimizing; Network productivity by providing information to the road user etc.

PURPOSES(continues)

Other Purposes: Estimation of highway usage

Measurement of current demand of a facility

Estimation of trends

Economic feasibility evaluation

Computation of accident rates etc.

Scope Of Traffic Volume Studies:

Scope

Magnitudes, classifications and

the time and directional split of

vehicular flows

Hourly, daily, yearly and seasonal

variation of vehicular flows

Flow fluctuation on different

approaches at a junction

Proportions of

vehicles

MethodologyTraffic volume study

Automatic Counting Method

Contact system based

Contactless system based

Manual Counting Method

Direct Method

indirect Method

Manual Counting Method: Direct method

Data is counted by using hand tally and manual counters/enumerators.Advantages: By this method traffic volume as well as

vehicle classification and turning proportions can be obtained. Data can be used immediately after collection.

Disadvantages: This method is not practicable for long duration count and when flow is high. Error is common especially when volume is high. Count cannot be cross checked. Count cannot be done in bad weather.

Mechanical Counting Boards

Mechanical count boards consist of counters mounted on a board that record each direction of travel. Common counts include pedestrian, bicycle, vehicle classification, and traffic volume counts.

Electronic Counting Boards

Electronic counting boards are battery-operated, lighter, more compact, and easier to handle. They have an internal clock that automatically separates the data by time interval.

Instruments used in Direct method

Hand CounterInstrument to Measure Distance

Example of data collection in tally method.

Direct method

A Typical Data Sheet of Manual Method

Manual Counting Method: Indirect Method

In this method, data is collected using video camera. Video is captured for long time and data is collected later by rewinding. Advantages: Besides traffic volume, several traffic

parameters can be obtained from recorded film. Data can be cross checked and quality can be ensured. This method is applicable when volume is high. It is suitable for non-lane based traffic operation.

Disadvantages: A suitable elevated place is required for filming operation. Data cannot be used immediately after collection.

Manual Counting Method: Indirect Method

Video cameras are mounted to record the traffic condition on a road.

Automatic counting method: In this method, vehicles are counted automatically without any human involvement. Contact system based (pneumatic, mechanical,

magnetic or piezoelectric method)Contactless system based (electrical/optical,

ultrasound/infrared radar, micro wave, CCTV/video image processing method etc.)

• Advantages: This method is suitable for long duration or continuous count. Count is not affected by bad weather condition.

• Disadvantages: It requires strict lane discipline. Non motorized vehicles are hard to detect

Equipment used for Automatic counting method: Contact system

Pneumatic Road Tube Counter

Motion sensors

Equipment used for Automatic counting method: Contactless system

Vehicle numbers are recorder using ultrasound, light beam or other infrared technology.

Data collection

Data: May, 2012Group no: 3Group Member: 7Location: Russel squareMethod: Manual counting method (Direct)Equipment: Stop watch; Data sheet.Weather: Partly cloudy

Data collection

Survey location and our group position

Reconnaissance Survey►The number of private

car is predominant in this

road; second most available

vehicle along this road is Rickshaw.

►There is a foot over bridge

used by Square Hospital.

►There are a number of

commercial buildings, shops,

on both side of the road

Reconnaissance survey►Abrupt movement of Pedestrian.

► Traffic flow at intersectionsare controlled by police.

Bar chart of vehicle composition

Bus(B)

Truck

(T)

Light V

ehicle...

Autoric

kshaw

...

Moto

rcycle

...NM

V

0

50

100

150

200

250

300

11 0

281

77

2241

32

Vehicle composition of traffic stream in percentage.

Bus(3%)Light Vehicle(64%)NMV(9%)Motorcycle(5%)Autorickshaw(18%)

Bus 3%

Motorcycle 5%Auto rickshaw

18%

Light vehicle 64%

NMV 9%

Service flow rateType of vehicle

Number PCE Converted number

Light Vehicle 281 1 281

Autorickshaw 77 0.5 39

Bus 11 3 33

Motorcycle 22 0.1 3

NMV 41 0.5 21

Truck 0 0.75 0

Total 377

Traffic flow(10.20 AM-10.40 AM)=377 PCU

Service flow rate(11.00 AM-12.00 PM)=377*3=1131 PCU/hr

Series10

200

400

600

800

1000

1200

From Panthapath to Russell SquareFrom Russell Square to PanthapathAverage

Time

PCU

/hr

PCU/hr VS. Time Graph

Level of service

LOSService Flow Rate

(PCU/hr)

A 600

B 700

C 900

D 1200

E 1400

F >1400

According to the calculated service flow rate the level of service during survey period was D.

Directional distribution

Direction TimePCU/hr

Average PCU/hr

Directional Distribution

From PanthaPath to Russell Square

9:00 AM-10:00 AM 860

963 54%10:00

AM-11:00 AM 900

11:00 AM-12:00

AM 1131

From Russell Square To Panthapath

9:00 AM-10:00 AM 726

807 46%10:00

AM-11:00 AM 856

11:00 AM-12:00

AM 837

Se-ries

1

0102030405060708090

100

Column1

Russell Square To Panthapath

ADT, AADT

Estimate 24-hr volume using the hourly expansion factors= {(860+726) * 18.8 + (900+856)*17.11 + (1131+837)*18.52}/6 = 16052Adjust the 24-hr volume for Thursday to an average volume for the week using the dailyexpansion factorsTotal weekly volume = 16052 *7.012= 112557

ADT, AADT(continues)

Average 24-hr volume (or Average Daily Traffic, ADT) = 112557/7= 16080Since the data were collected in May, using the monthly expansion factors for MayAnnual Average Daily Traffic (AADT) = 16080*1.395= 22432So, obtained value of Average Daily Traffic,(ADT) is 16080 PCU/day and AnnualAverage Daily Traffic,(AADT) is 22432 PCU/day.

ADT, AADT(continues)

ADT AADT

16080 22432

ADT, AADT (continues)

Direction ADT AADT

Panthapath to Russell Square 17,534 24,460

Russell Square to Panthapath 14,623 20,400

Series1012345678

From Panthapath to Russell squareFrom Russell Square to Pan-thapathAverage

% A

DT

9.00-10.00 10.00-11.00 11.00-12.00

Flow Fluctuation Curve

Conclusion

Vehicle composition : Light vehicles (Car, Jeep, etc.) occupied 64% of total

vehicle. Percentage of Auto rickshaw is relatively high. Percentage of Public transport is very low.

Conclusion(continues)

Level of Service:• The LOS of the road is D• The road was constructed to serve as a

Collector road.• Collector road should have a LOS C.

Conclusion(continues)Directional Distribution: Directional distribution was found nearly equal (54% and 46%) in both side of the road. So it can be said that the geometric design of the road is adequate for present traffic.

Flow Fluctuation Curve: From the flow fluctuation curve it is seen that the vehicle movement is nearly uniform in that road. %ADT is highest for Panthapath to Russel Square direction at 11.00-12.00.

Conclusion(continues)Recommendation:• NMV should not be allowed• Amount of public transport should be increased. • To increase the LOS necessary steps should be taken

to prevent the entrance of NMV, stop road side parking, prevent pedestrian crossing; introduce optimum traffic signal system.

• Construct foot over bridges at necessary point for pedestrian crossing.

Limitations

Short count was taken (20 min) Now a days automatic counting method based on

CCTV/Video image processing is reliable and popular. But due to resource constraint it was not possible.

Limited and unskilled enumerators.