volume study (group 5)

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