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AHSANULLAH UNIVERSITY OF SCIENCE AND TECHNOLOGY
DEPERTMENT OF CIVIL ENGINEERING
VOLUME STUDY
CE : 452Course Name : Transportation Engineering Sessional 2Course Teacher : Mudasser Seraj Rafi
Group : 5
WE THE GROUP MEMBERS:
Afsana Israt Khan 10.01.03.039
Sohel Rana 10.01.03.043
S.M.Rahat Rahman 10.01.03.044 Muntasir Rahman 10.01.03.045 Sajid Anwar Anik
10.01.03.046 Mohtasimur Rahman
10.01.03.040 Nasim Anjum Swapnil
08.01.03.106 Ezaz Ahmed
10.01.03.041
RAHAT
Anik
Mohotasimur
Muntasir
Traffic Volume Study
Is Presented By
Contents >>
• Introduction• General Objectives of Traffic Volume Study• Study Site• Methodology• Survey procedure• Data Collection• Analysis of collected data• Conclusion• Recommendations• Limitations of the Study
Traffic Survey
Traffic surveys are required to transportation engineers for :
planning and designing traffic facilities
determining the need for traffic control devices
studying the effectiveness of introduced schemes;
diagnosing given situations and finding appropriate solutions;
forecasting the effects of projected strategies;
calibrating and validating traffic models etc.
Traffic Stream characteristics – volume, speeds, density, and occupancy studies etc.
Axle load survey Capacity studies of streets and intersections Travel demand – Home interview survey Studies of road users cost Parking supply and demand studies Inventories of road-traffic physical features Traffic accident studies Environmental impact studies of transport System usage studies
Classification of Traffic Survey
Traffic Volume Study
Objectives of Study
Vehicle Composition Traffic Stream Properties
Average Daily Traffic
Directional Distribution Flow Fluctuation
Introduction
Traffic volume studies are conducted to determine the volume of traffic moving on the roads and classifications of roadway vehicles at a particular section during a particular time.
Volumes of a day or an hour can vary greatly, depending on the different day of the week or different time period of a day.
Traffic Volume survey is the determination of the number, movement and classifications of roadway vehicles at a given location.
SPECIFIC OBJECTIVES
To determine vehicle composition during survey period
To determine service flow rate in PCU unit
To determine Directional Distribution of traffic
To estimate average daily traffic based on expansion factor
To draw partial flow fluctuation curve
General Objectives
A. Design Purposes
B. Improvement Purposes
A. Planning Purposes
C. Dynamic Traffic Management Purposes
Structural and geometric design of pavements, bridge, and other
highway facilities.
Intersection design including minimum turning path, channelization,
flaring, and traffic control devices.
Pedestrian volume study is useful for designing side-walks, pedestrian
crossing etc.
A . Design Purposes
• To allocate limited maintenance budget rationally, it is important to know the traffic volume carried by a particular roadway section in order to decide the importance of the road and fixing its relative priority.
• In order to improve the roadway operating condition, it is important to know the traffic volume –
• To examine the existing operating/service condition of a roadway section.
• To check the need (warrant) traffic control devices.
• To determine the type of improvement measure need to be taken. • To measure the effectiveness of a traffic control measure.
B. Improvement Purposes
Planning Purposes
Accurate information on the amount of traffic on the roads is vital for the planning of both road maintenance and improvement policies
Traffic volume network analysis helps in deciding/planning if there is need for Improvement and Expansion in terms of construction missing links, by-pass, alternative road etc.
Dynamic Traffic Management Purposes
Up to date and continuous flow/congestion information is essential for optimizing - Traffic signal design and thereby improving junction performance and Network productivity by providing information to the road user.
C. Planning Purposes & D. Dynamic Traffic Management Purposes
Estimation of highway usage and measurement of current demand of a facility.
Estimation of trend.
Economic feasibility evaluation.
Computation of accident rates.
Other Purposes
Scopes of Volume Study
SCOPES
Design
Planning
Improvement
Dynamic Traffic
Management
Estimating Highway Use
Computing Accident
Rates
Traffic Stream
Keywords Related To Volume Study
Volume/flow
Rate of flow
Average Daily Traffic (ADT )
Average Annual Daily Traffic (AADT)
Design Hourly Volume
Service flow rate
Directional Distribution
Methods of Counting
Manual methods
Combination of manual and mechanical methods
Automatic devices
Moving observer method
Photographic method
Main Methods of Counting
• 1. Direct Method• 2. Indirect Method
Manual Counting Method
• 1. Contact System• 2. Contact-less System
Automatic Counting Method
Manual Count Recording Method(Filled Data Sheet and Summary Sheets)
Figure: Example Manual
Intersection Volume
Count Tally Sheet
Tally Sheets
Mechanical Counting Boards
Mechanical count boards consist of counters mounted on a board that record each direction of travel.
Figure : Manual Counting Board
Electronic Counting Boards
Electronic counting boards are battery-operated, hand-held devices used in collecting traffic count data.
Figure : Electronic Counting Boards
Steps to a manual traffic volume count
1. Prepare :
Determine the type of equipment to use, the field procedures
to follow, and the number of observers required.
Label and organize tally sheets
2. Select observer location(s) :
Observers (data collectors) should be positioned where they
have a clear view of traffic and are safely away from the edge
of the roadway.
3. Record observations on site.
Automatic Counting Methods
An automatic survey involves placing a tube or loop across a road which is connected to a box containing the means for storing the information.
In this method, vehicles are counted automatically without any human involvement.
There are two techniques of automatic counting: a) Contact
system based on pneumatic, mechanical, magnetic or piezo-
electric method and b) Contactless system based on
electrical/optical, ultrasound/infrared radar, micro wave,
CCTV/video image processing method etc.
Automatic Count Recording Methods
Portable Counters
Videotape
Permanent Counters:
Automatic Counting Method
Bending plate
A weight pad attached to a metal plate embedded in the road to measure axel weight and speed. It is an expensive device and requires alteration to the road bed.
Figure : Bending Plate
Pneumatic road tube
Pneumatic road tube sensors send a burst of air pressure along a
rubber tube when a vehicle's tires pass over the tube.
Figure : Pneumatic Road Tube
Smart Sensor HD device
Using radar technologies, Smart Sensor HD devices have the capability of detecting vehicles (Contactless System)
Piezo-electric sensor
A device that is placed in a groove cut into the roadbed of the lane(s) being counted. This electronic counter can be used to measure weight and speed.
Figure : Piezo-electric Sensor
Inductive loop
The inductive loop detector (ILD) is the most common sensor used in traffic management applications.
Figure : Inductive loop
Count Vehicles Using Hand-Held Electronic Counter Boards
Figure Count Vehicles Using Hand-Held Electronic Counter Boards.
Piezo-electric sensor
Figure : Piezo-electric Sensor
A device that is placed in a groove cut into the roadbed of the lane(s) being counted. This electronic counter can be used to measure weight and speed.
Data Collection
Survey Location
Study Location:Panthapath Road Segment between
Russell Square and Green road-Panthapath Intersection
Information about Data Collection
Survey Date : 24th November, 2013
Survey route : Russell Square to Panthapath
Method :Manual Method using hand tally and manual counters
Equipment : Hand Counter , Pencil , Clip Board ,
Data Sheets
No. of enumerator : 8 persons
Equipment Needed
Hand Counter
Supply of blank field data sheets
Pencils , erasers and pencil sharpner
Clip boards.
RECONNAISSANCE SURVEYS
Reconnaissance survey and route
alignment survey was carried out to acquire
generalized idea about the survey area.
This survey ensures the physical
properties of location which cannot be
authenticated by Google Earth Maps.
RECONNAISSANCE SURVEYS
Private car is predominant in this road .
Most available vehicle along this road is motorcycle.
RECONNAISSANCE SURVEYS
Two private hospital, Square Hospital and Shomorita Hospital, is situated alongside the road . So that traffic attraction is huge in this area.
No foot over bridge in this road .
Geometric Layout of Intersection
Panthapath Intersection (Units in meter)
Geometric Layout of Intersection
Panthapath Intersection (Units in meter)
Geometric Layout of Intersection
Russel Square Intersection (Units in meter)
Geometric Layout of Intersection
Russel Square Intersection (Units in meter)
Pilot survey is a small scale preliminary survey.
It is conducted in order to evaluate feasibility, time, cost, adverse
events, and affect size in an attempt to improve upon the study
design prior to performance of a full-scale research project.
A pilot study is usually carried out on members of the relevant
population, but not on those who will form part of the final sample. .
A pilot experiment/study is often used to test the design of the full-
scale experiment which then can be adjusted
Pilot Survey
Counting Method
Amongst the two methods of traffic counting (Manual and Automatic),
Manual traffic count has been selected.
Required materials for automatic traffic count cannot be obtained
from AUST.
Again, available automatic traffic counting machines were not fully
functional. Considering the circumstance, the manual method of
traffic count was the best possible option.
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• Not costly• Easy to collect data
Figure : Hand Tally Counter
Survey Procedure
Number of Enumerator
There were 8 enumerators in each group. Every enumerator was appointed to count one or more
than one category of vehicle.
Data Analysis
Vehicle Composition in Traffic Stream
Service Flow Rate in PCU/ PCE unit
ADT based on Expansion Factors
Directional distribution
Flow Fluctuation Curves
Traffic Volume Count Data
Date : 31 May, 2012
Station name: Russel
Square to Panthapath
Day : Thursday Survey group: Group 5
Time : 10:00 AM-10 :
20 AM
Weather condition:
Cloudy
Cycle
Time
1 2 3 4 5 6
Total traffic in a cycle
Bus (B)
Truck (T)
Light Vehicle (LV)
Auto Rickshaw (AR)
Motorcycle (MC)
NMV
1 10:00 -10 : 20 8 0 203 47 43 39 340
Vehicle Composition of Traffic Stream
2%
60%14%
13%
11%
Pie Chart for Vehicle Composition of Traffi c Stream
Bus (B) Trcuk (T) Light Vehicle (LV)Auto Rickshaw (AR) Motorcycle (MC) NMV
Service Flow Rate
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 >> It is the equivalent hourly rate at which vehicle pass over a given point or section of a lane or roadway during a given time interval less than 1 hr, usually 15 min while maintaining a designated level of service.Importance of Flow Rate >> A short duration count (for e.g. 15 minutes count) can be converted into an equivalent hourly rate
Service Flow Rate
Type of Vehicle Number PCE Converted number
Bus (B) 8 3 24
Tract (T) 0 .75 0
Light Vehicle(LV) 203 1 203
Auto Rickshaw (AR) 47 .5 23.5
Motorcycle (MC) 43 .1 4.3
NMV 39 .5 19.5
Total 340 274.3
Service Flow Rate
Traffic Flow (10:00-10:20 AM) 274.3 PCU
Service Flow Rate (10:00-11:00AM) 823 PCU/hr
From calculation it is found that the service flow rate of this corridor at 10:00am to
11:00 am was 823 PCU/hr. Again, level of service of a road can be determined
from service flow rate. Level of service of a road can be classified according to
service flow rate as below
LEVEL OF SERVICE VS SERVICE FLOW RATE
LOS Service Flow Rate (PCU/hr)
A 600
B 700
C 900
D 1200
E 1400
F >1400
According to this table the level of service of Panthapath road was, “C” at 10:00 am-
11:00 am in Thursday.
Directional Distribution (DD)
Directional Distribution >>
The directional Distribution is defined as the percentage of
heavier volume over the total highway volume.
Importance of Directional Distribution >> • Accounts for the directional distribution of traffic• Used to convert average daily traffic to directional peak hour traffic
Proportion of Directional Distribution of Traffic Flow
55%
45%
Proportion of Directional Distribution of Traffi c Flow
From Panthapath To Russell Square From Russell Square To Panthapath
Directional Distribution
Direction Time PCU/hAverage PCU/hr
Directional
Distribution
From Panthapath To Russell
Square
9:00AM-10:00AM
860
961.67 78.38%10:00AM-11:00AM
899
11:00AM-12:00AM
1126
From Russell
Square To Panthapath
9:00AM-10:00AM
727
795.67 21.61%10:00AM-11:00AM
823
11:00AM-12:00AM
837
Directional Distribution
According to directional distribution most of the vehicle travel towards
Russell Square, as this road leads to the city center and the survey was
made in the work going phase of the day, so directional distribution was
justified.
Flow Fluctuation Curve
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 ADT
Flow Fluctuation Curve
9:40-10:00 AM 10:00-10:20 AM 10:20-10:40AM600
700
800
900
1000
1100
1200
859.5
898.8
1125.6
726.6
822.9 836.7
793.1
860.9
981.2
Flow Fluctuation Curve (PCU/hr vs. time curve)
From Panthopath to Russell Square From Russell Square to PanthopathAvg. PCU
PC
U/h
r
ConclusionsRecommendations
Limitations
Conclusions
Discussion on Vehicle volume
The vehicular volume using Panthapath road – Russell square road is important
for understanding the efficiency at the system works at present and the general
quality of service offered to the road users. The vehicle count has one cycle. It
was a matter fact that number of vehicle counted in cycle cannot determine the
highest number of vehicle passed through the survey location in the cycle of
counting period.
Discussion on Vehicle Composition
From the pie chart of Vehicle composition, it is obtain that sixty percent of total traffic was light vehicles. This indicates the proximity of the location to residential area of high income group people. Only fourteen percent was Auto-rickshaw. Buses were almost fully occupied. It can be assumed that, more people were travelling by bus from distance places. About eleven percent of total vehicles were NMT. Scarcity of public transport in this area gives rise to the dependency on NMT. NMT creates congestion and lower speed. Lower speeds cause economic loss to the community due to the time lost by the occupants of the vehicles and the high operational cost of vehicles. Congestion often leads to traffic hazzrds.Truck and buses has restrictrd maneuverability, reduce the number of vehicles that a facility can handle. Vehicle occupancy surveys are easy to conduct for cars and motorised two wheelers. The observers can note the number of occupants of everyone of such vehicles bystanding by the roadside
Discussion on Directional Distribution
78 percent of traffic flow was towards Russell Square which indicates turblent flow towards north-west. It was morning rush hour. So flow was higher towards the city center. 22 percent of traffic was flowing towards south-east. If another vehicle count was done in evening rush hour, opposite scenario might be seen.
Discussion on Flow Fluctuation
To draw flow fluctuation curve, it was assumed that volume for three continuous hours were counted, although all vehicles were counted within one hour. Each group counted vehicles for 20 minutes in each direction. Flow rates were calculated from that short count data and plotted. The flow fluctuation curve shows a peak at 10:00-11:00 hrs.
Knowing the flow characteristics, we can determine wheather Panthapath to Russell square section of the road at 10:20-10:40 AM is handling traffic much above its capacity; the traffic is heavy so that the road suffers from congestion with consequent loss of journey speeds.
Scope for Further Study
This volume study was practiced by un-skilled enumerators, which may lead to some error in data collection process. values are not amenable to easy analysis by computers
Data collected by manual method of counting, which is unreliable and irreversible, more representatives and reliable data could be obtained if automatic data collection method were followed.
For continuous and long term study , maual metod is not suitable.for authentic value, automatic device is needed.
The composition of traffic stream varies from site to site. Specific vehicular movements such as left turns, right turns, sraight- aheads etc are not recorded. Data were collected for short-term (20 minute), which was not representative to the flow characteristics of the road. If 3days continuous data were collected, that would me much more representative than this short count of traffic volume.
The ADT and AADT value are not analysed . Short term variations occuring in the course of a day , and especially the peaking situations in the morning and evening rush hours are needed for design of traffic control systems are complicated intersections.
Limitations of the study
Direct Manual method being less accurate.
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 regulation is not obtained.
Recommendations
This road mainly served the purpose of collector road. Collector roads should be designed for a level of service C or better.From the data analysis , we can see the Level of Service is C
The traffic flow is stable with marked restriction Driver’s selection of speed and reduced ability to pass is reduced.
The volume count must contain more than one cycle to get more authentic value
Manual count method required trained enumerators, which was not available in this case
For more reliable data automatic data collection process should be used.
Data were collected for 20 minutes by each group, which may not represent the hourly fluctuation of traffic, so for more allegorical data one hour data should be taken.
More public transport facility should be provided to support the need of inhabitants living the residential area near the road.
The LOS is D is acceptable . If the level of service is D, even during off-peak hour. the situation handicaps the serviceability of the road
NMT should be prohibited in this road which will help to increase the Level of Service and Travel Speed.
Thank you.
Dedicated this presentation to Sami Sir and Rafi Sir