A brief description on traffic volume study.

1. AHSANULLAH UNIVERSITY OF SCIENCE & TECHNOLOGY
DEPARTMENT OF CIVIL ENGINEERING
TRAFFIC VOLUNE STUDY
TRANSPORTATION ENGINEERING SESSIONAL II
COURSE NO. CE 452
GROUP NO : 3
SECTION : B
YEAR/SEMESTER : 4/2
COURSE TEACHERS:
MR. MUDASSER SERAJ
LECTURER, AUST

2. Presentation outline
►Definition ►Objective
►Scope ►Methodology ►Data collection
Reconnaissance Survey ►Data analysis ► Conclusion
►Limitations

3. Definition
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.

4. 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)

5. 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.

6. 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

7. 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.

8. 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.

9. 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

10. 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.

11. 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.

12. Scope Of Traffic Volume Studies:
Magnitudes,
classifications
and the time
and directional
split of
vehicular flows
Proportions of
vehicles
Scope
Flow
fluctuation on
different
approaches at a
junction
Hourly, daily,
yearly and
seasonal
variation of
vehicular flows

13. Methodology
Automatic
Counting
Method
Traffic volume
study
Contact system
based
Contactless
system based
Direct Method
Manual
Counting
Method
indirect Method

14. 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.

15. 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.

16. 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.

17. Instruments used in Direct method
Hand Counter
Instrument to Measure
Distance

18. Example of data collection in tally method.

19. Direct method
A Typical Data Sheet of Manual Method

20. 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.

21. Manual Counting Method: Indirect Method
Video cameras are mounted
to record the traffic condition
on a road.

22. 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

23. Equipment used for Automatic counting
method: Contact system
Motion sensors
Pneumatic Road Tube
Counter

24. Equipment used for Automatic
counting method: Contactless system
Vehicle numbers are recorder using ultrasound, light beam or other
infrared technology.

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

26. Data collection
Survey location and our group position

27. 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

28. Reconnaissance survey
►Abrupt movement of
Pedestrian.
► Traffic flow at intersections
are controlled by police.

29. Bar chart of vehicle composition
300
281
250
200
150
100
77
50
0
11
0
22
41
32

30. Vehicle composition of traffic stream
in percentage.
Light vehicle 64%
Bus(3%)
NMV 9%
Auto rickshaw
18%
Bus 3%
Motorcycle
5%
Light Vehicle(64%)
NMV(9%)
Motorcycle(5%)
Autorickshaw(18%)

31. Service flow rate
Type 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

32. PCU/hr VS. Time Graph
1200
1000
PCU/hr
800
600
From Panthapath to
Russell Square
400
From Russell Square to
Panthapath
Average
200
0
Time

33. Level of service
LOS
Service 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.

34. Directional distribution
Direction
PCU/ Average Directional 100
hr PCU/hr Distribution
Time
9:00 AM10:00 AM 860
10:00
From PanthaPath AM-11:00
900
to Russell Square
AM
11:00
AM-12:00
1131
AM
9:00 AM10:00 AM 726
10:00
From Russell
AM-11:00
Square To
856
AM
Panthapath
11:00
AM-12:00
837
AM
80
963
54%
60
40
20
0
807
46%

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

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

37. ADT, AADT(continues)
ADT
AADT
16080
22432

38. ADT, AADT (continues)
ADT
AADT
Panthapath to
Russell Square
17,534
24,460
Russell Square to
Panthapath
14,623
20,400
Direction

39. % ADT
Flow Fluctuation Curve
8
7
6
5
4
3
2
1
0
From Panthapath
to Russell square
From Russell
Square to
Panthapath
Average
9.00-10.00
10.00-11.00
11.00-12.00

40. 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.

41. 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.

42. 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.

43. 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.

44. 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.