1 nrrnrm1 0000073614

The Analysis on the Performances of Signalised Intersection at Taman Tas

BRENDON SOON GHIM ENG

A thesis is submitted in partial fulfillment of the

requirement for the award of the degree of

Bachelor of Civil Engineering

Faculty of Civil Engineering & Earth Resources

Universiti Malaysia Pahang

MAY2011

vi

ABSTRACT

Malaysia is one of the developing countries in the world. Currently, Malaysia is

taking into a massive fast track development so is the change in traffic conditions in this

country. The operating characteristics of this system are functionally dependent upon the

amount of types of users that require services. This is especially true at that point where

elements of the system come together that is the intersection. The Malaysian citizens like

to have their own transport and creating typical travel behaviour compare with other

countries. When traffic volumes increase or change their nature, it is usually the

intersection that fust proves itself incapable of serving the added or altered demand.

Consequently, congestion will increase during peak hours and causes delays. Therefore,

signalised intersections are an important part of road system in Malaysia. The signalised

intersection at Tarnan Tas has come to an alert for traffic engineers to come in and

analysed the cause of delay and find a solution of ease the delays during the peak hour

traffic. Hence, this study is made in order to analyse on the performances of the

signalised intersection in terms of Level of Service and delays. After the study is made

and the results of the Level of Service are obtained, an alternative solution is proposed in

the data analysis to reconstruct the existing signalised intersection.

vii

ABSTRAK

Malaysia merupakan salah satu negara yang sedang membangun standing dengan

negara yang maju di dunia. Malaysia kini berada pada tahap kemajuan pada masa

sekarang sama juga dengan keadaan trafik yang mengakibat kesesakan jalan raya di

negara ini. Sistem ini beroperasi mengikut bilangan dan jenis pengguna jalan yang sangat

memerlukan kemudahan jalan raya seperti persimpangan trafik. Semua pengguna jalan

raya di Malaysia memilih untuk memiliki kenderaan sendiri dan mempunyai sifat-sifat

tersendiri ketika memandu di jalan raya berbanding dengan pengguna jalan raya di negara

lain. Apabila kenderaan telah meningkat secara mendadak di negara ini, persimpangan

trafik merupakan sistem yang dapat mengawal bilangan kenderaan yang melalui setiap

persimpangan. Kesesakan jalan raya selalunya berlaku pada masa waktu bekerja pada

waktu pagi dan masa balik dari kerja pada waktu petang. Oleh sebab itu, persimpangan

trafik merupakan kemudahan jalan raya yang sangat penting di Malaysia. Akan tetapi,

persimpangan trafik di Taman Tas Kuantan adalah berada pada tahap yang

membimbangkan semua pihak iaitu pengguna jalan raya. Bilangan kenderaan yang

melalui persimpangan tersebut telah menyebabkan kesesakan yang sangat

membimbangkan. Oleh sebab itu, kertas kerja ini adalah untuk menyelidik keadan LoS di

persimpangan tersebut. Selepas mendapat keputusan LoS tersebut, maka proses

penyelesian akan diberi dalam kaji selidik ini untuk meningkatkan LoS di persimpangan

terse but.

viii

TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION 11

DEDICATION IV

ACKNOWLEDGEMENT v

ABSTRACT VI

ABSTRAK Vll

TABLE OF CONTENTS Vlll

LIST OF TABLES Xll

LIST OF FIGURES xv

CHAPTER! INTRODUCTION

I. I Background of Study I

I .2 Study Objectives 3

I .3 Problem Statement 3

I .4 Scope of Study 4

I .5 Significant of Study 4

ix

CHAPTER2 LITERATURE REVIEW

2.1 Introduction 5

2.2 Traffic Signal 6

2.3 Types of Signal 6

2.3.l Pre-timed/Fixed Signalised System 6

2.3.2 Traffic-actuated Signalised System 7

2.3.3 Traffic-adjusted System 7

2.4 Traffic Signal Control 8

2.5 Signal Display and Location 8

2.6 Signal Display Requirement 9

2. 7 Geometric Design of Signalised Intersections 9

2.8 Traffic Control and Analysis at Intesections 10

2.9 Signalised Intersection 11

2.10 At-grade Intersection Characteristics 12

2.11 Capacity oflntersections 12

2.12 Analysis of Traffic at Signalised Intersections 13

2.12.1 Saturation Flow Rate 13

2.12.2 Peak Hour Factor 14

2.13 Level of Service 15

2.14 Determining Delays 17

2.l4.1 Uniform Delays 18

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2.14.2 Incremental Delays 18

CHAPTER3 METHODOLOGY

3 .1 Introduction 19

3 .2 Site Accessibility 20

3.3 Flow Chart 23

3.4 Data Collection 24

3.4.l Pilot Survey 24

3.4.2 Intersection Geometry Survey 24

3.4.3 Traffic Count Survey 25

3.5 Data Processing and Evaluation 26

CHAPTER 4 RESULTS AND DISCUSSION

4.1 Introduction 27

4.2 Traffic Survey Data Analysis 28

4.2.1 AM and PM Peak Hour Traffic for Cars 28

4.2.2 AM and PM Peak Hour Traffic for Motorcycle 31

4.2.3 AM and PM Peak Hour Traffic for Trailers 33

4.2.4 AM and PM Peak Hour Traffic for Lorries 35

4.2.5 AM and PM Peak Hour Traffic for Buses 37

4.2.6 AM and PM Peak Hour Traffic according to 39

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Vehicle Classification

4.3 Traffic Signal Program 41

4.3.1 Junction Layout 41

4.3.2 Junction Information 42

4.3.3 Vehicles Volume and Adjustment 44

4.3.4 Actual Condition Saturation Flow Rate 46

4.3.5 Actual Condition Saturation Degree 48

4.3 .6 Actual Condition Cycle Length Design 49

4.3.7 Actual Condition LoS Determination 50

4.3.8 Proposed Solution Saturation Flow Rate 53

4.3.9 Proposed Solution Saturation Degree 54

4.3.10 Proposed Solution Cycle Length 55

4.3.11 Proposed Solution LoS Determination 56

CHAPTERS CONCLUSION AND RECOMMENDATION

5.1 Introduction 58

5.2 Conclusion 59

5.3 Recommendation 60

REFERENCES 61

GLOSARRY 63

APPENDIX 66

xii

LISTS OF TABLES

TABLE NO. TITLE PAGE

Table 2.1 LoS Criteria for Signalised Intersection 17

Table 4.1 AM and PM Peak Hour Traffic for Cars 28

Table 4.2 AM and PM Peak Hour Traffic for Motorcycles 31

Table 4.3 AM and PM Peak Hour Traffic for Trailers 33

Table 4.4 AM and PM Peak Hour Traffic for Lorries 35

Table 4.5 AM and PM Peak Hour Traffic for Buses 37

Table 4.6 AM and PM Peak Hour Traffic for Vehicle Classification 39

Table 4.7 AM Peak Hour Junction Information 42

Table 4.8 PM Peak Hour Junction Information 43

Table 4.9 AM Peak Hour Vehicles Volume and Adjustment 44

Table 4.10 PM Peak Hour Volume and Adjustment 45

Table 4.11 AM Peak Hour Saturation Flow Rate 46

Table 4.12 PM Peak Hour Saturation Flow Rate 46

Table 4.13 AM Peak Hour Saturation Degree 48

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Table 4.14 PM Peak Hour Saturation Degree 48

Table 4.15 AM Peak Hour Cycle Length Design 49

Table 4.16 PM Peak Hour Cycle Length Design 49

Table 4.17 AM Peak Hour LoS Determination 50

Table 4.18 PM Peak Hour LoS Determination 51

Table 4.19 Alternative Model AM Peak Hour Saturation Flow Rate 53

Table 4.20 Alternative Model PM Peak Hour Saturation Flow Rate 53

Table 4.21 Alternative Model AM Peak Hour Saturation Degree 54

Table 4.22 Alternative Model PM Peak Hour Saturation Degree 54

Table 4.23 Alternative Model AM Peak Hour Cycle Length Design 55

Table 4.24 Alternative Model PM Peak Hour Cycle Length Design 55

Table 4.25 Alternative Model AM Peak Hour LoS Determination 56

Table 4.26 Alternative Model PM Peak Hour LoS Determination 56

Table Al Adjustment Factor for Average Lane Width (fw) 67

Table A2 Adjustment Factor for Grade (fg) 67

Table A3 Adjustment Factor for Area Type (fa) 68

Table A4 Adjustment Factor for Left Tum and Right Tum (fLT 68

and fRT)

Table AS Level of Service Based on VIC Ratio 68

Table A6 Traffic Signal Setting Formula 69

Table Bl Vehicle Composition Correction Factor fears Based on 71

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Proportion (%) of Cars in Flow

Table B2 Vehicle Composition Correction Factor fmotors Based on 72

Proportion (%) of Motorcycles in Flow

Table B3 Vehicle Composition Correction Factor ftraiters Based on 73

Proportion(%) of Trailers in Flow

Table B4 Vehicle Composition Correction Factor fiorries Based on 74

Proportion (%) of Lorries in Flow

Table B5 Vehicle Composition Correction Factor fbuses Based on 75

Proportion (%) of Buses in Flow

xv

LISTS OF FIGURES

FIGURE NUMBER TITLE PAGE

Figure 3.1 Local and Regional Road Network 21

Figure 3.2 Junction Layout for Chapter 3 Review 21

Figure 3.3 Project Methodology Flow Chart 23

Figure 3.4 Location of Observers 25

Figure 4.1 Junction Layout for Chapter 4 Review 41

1

CHAPTER I

INTRODUCTION

1.1 Background of Study

Malaysia is one of the developing countries in the world. Currently, Malaysia is

taking into a massive fast track development so is the change in traffic conditions in this

country. The operating characteristics of this system are functionally dependent upon the

amount and types of users that require service. This is especially true at that point where

elements of the system come together that is the intersection. The Malaysian citizens like

to have their own transports and creating typical travel behaviour compare with other

countries. When traffic volumes increase or change their nature, that is increase in the

number of heavy vehicles like big trucks and buses, it is usually the intersection that frrst

proves itself incapable of serving the added or altered demand. Consequently, delay will

increase during peak hours traffic. That is theoretically and practically logical because the

intersection is a concentrated conflict point which generally functions at a lower capacity

and level of service than any of the road segment it serves (Arahan Teknik Jalan 11 ,

1987). Therefore, signalised intersections are an important part of road system in

Malaysia. Efficient traffic networks enable all sorts of people to reach their destination

faster, and ensure a good and safe transportation road system. Their capacity controls the

volume of traffic within the network system (Arahan Teknik Jalan 11, 1987). It acts as a

bottleneck to the satisfactory operation of the adjacent highway system. Thus, a detailed

2

study on the performance of the signalised intersection can be conducted to assess the

effectiveness of an intersection based on local traffic condition.

Kuantan is the state capital of Pahang, the largest state in Peninsular Malaysia. It

is situated at the east coast of Malaysia near the mouth of the Kuantan River and faces the

South China Sea. Kuantan-Gambang by-pass is the road connecting Gambang to Kuantan

and vice versa. The increasing numbers of road users coming to kuantan from various

places like Kuala Lumpur, Temerloh, Karak, Bentong, Terengganu, Segamat, and Johor

have contributed in the arising of transportation activity.

Taman Tas is a small residential area. It is located at 15 kilometers from Kuantan.

Basically, Taman Tas consists of facilities like shop-houses, mini-supermarket, petrol

station, food stalls, banks, school, bus stop, and taxi stand. The road connecting to this

residential area is Kuantan-Gambang by-pass. At Taman Tas, there is a three-legged

signalised intersection or T-Junction. This junction is very busy during peak hour traffic.

The traffic delay that occurs at the Taman Tas intersection varies significantly when the

traffic demands increases every year. The main factor contribute to the delay is that the

population in that area is growing significantly.

3

1.2 Study Objectives

• To analyse the performances of a signalised intersection based on local traffic

conditions in terms ofLoS.

• To provide a satisfactory operating performance prior to the actual condition.

1.3 Problem Statement

Nowadays, the road connecting to Kuantan and Gambang and vice versa is very

congested during peak hours. The road is categories as 2-way-2-lane road. Upon reaching

the signalised intersection at Taman Tas, it becomes a multi-lane intersection. The

condition of the traffic is measured by Level of Service. Generally, the Level of Service

(LoS) is used to measure the efficiency of traffic flow through intersections, along routes,

and in road network. The LoS on the existing road will become worsen by the increasing

amount of vehicles passing through that signalised intersection.

The signalised intersection might not give any adequate or optimum signal timing

when it is practically operating in real situation. Problems such as inadequate given limit

with respect to the traffic volume can cause the traffic delay. Therefore, there is a need to

begin to perform study on the existing intersection based on the LoS, and delays enable

us to categories the efficiency of the signalised intersection in order to improve the

performance of the existing signalised intersection.

4

1.4 Scope of Study

Generally, the scope for this study is to analyse the performances of the signalised

intersection at Taman Tas intersection. Basically, this study would cover until the

determination of LoS and delays of peak hour traffic. The parameters such as number of

lanes, vehicles volume, saturation flow rate, saturation degree, cycle length, and level of

service are included in this study. Signal control data such as signal phasing and cycle

time will be observed throughout the collection of data on site.

In this study, traffic volume count will be done manually. Due to time constrained,

the traffic volume count study is conducted on one Wednesday, 3rd March 2011, during

the morning peak traffic hour from 7.00 a.m. to 9.00a.m and evening peak hour from 5.00

p.m. to 7.00 p.m. will be observed and analysed. The data is then used as input in the

Microsoft Excel spreadsheets as a simple method to analyse the performances of the

intersection controls.

1.5 Significant of Study

The results obtained from this study might be useful in finding solution to

improve the LoS from the current condition for the years to come as well as to improve

the traffic operation at Taman Tas intersection to ease the traffic delays. This will

definitely benefit to all users passing through Tarnan Tas signalised intersection as well

as the residents who live in the neighbourhood in Tarnan Tas and future growth of the

population in Kuantan.

5

CHAPTER2

LITERATURE REVIEW

2.1 Introduction

This chapter contains literature reviews, which discuss about the signalised

intersection, traffic signals, delays, analysis of signalised intersection, and level of service.

Basically, the basic types of at-grade intersections, three-legged intersections, which

consists of three approaches; four-legged or cross intersections, which consists of four

approaches, and multi-legged intersections, which consists of five or more approaches

according to Garber N. J . and Hoel L. A. (2002). Traffic signal controls most of the

power-operated devices except signs either mechanically or electrically. However, this

study will only improve the signalised intersection by taking into account the saturation

flow rate, saturation degree, cycle length and LoS based on Malaysian Highway capacity

Manual and JKR standard. The findings of this research have leads us to realise that there

are some factors contributing to the saturation flow of our roads thus affecting the

intersection capacity.

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2.2 Traffic Signal

Garber N. J. and Hoel L. A. (2009) said that one of the effective ways of

controlling traffic at intersections is the use of traffic signals. Basically, traffic signals can

be used to eliminate many conflicts because different traffic streams can be assigned the

use of the intersection at different times. Rogers M. (2008) explained that traffic signals

work on the basis of allocating separate time periods to conflicting traffic movements at a

highway intersection so that the available carriageway space is utilised as efficiency and

safety as possible.

2.3 Types of Signal

There are few types of traffic signals used to control the inter-crossing movement

at intersections. Those popular systems are pre-timed/fixed-time system, actuated system

and traffic adjusted system. The types of traffic signals can be found in Arahan Teknik

(Jalan) 13/87 of a guide to the design of traffic signals.

2.3.1 Pre-timed/Fixed-time Signalised System

Arahan Teknik (Jalan) 13/87 stated that this type of signal directs traffic to stop

and permits it to proceed in accordance with a single, pre-determined time schedule or a

series of such schedules. Besides, Arahan Teknik (Jalan) 13/87 also said that the traffic

signal is set to repeat a given sequence of signal indication regularly. In other word, this

type of traffic signal is a system where the time frame of green period and the cycle time

7

is determined at the beginning stage during the installation of traffic light. Even though

indication of each colour of signalised traffic is constant, it can vary due to different

circumstances.

2.3.2 Traffic-actuated Signalised System

Arahan Teknik (Jalan) 13/87 mentioned that the operation ofthis type of signal is

varied in accordance with the demands of traffic. According to Arahan Teknik (Jalan)

13/87, the green light period for one particular way is dependent on the traffic density on

the particular route or direction. Besides, Arahan Teknik (Jalan) 13/87 explained that the

sensor or other advanced devices will be installed at each arms of road that joined at the

intersection area. Through this system, the indication of green light for one phase will be

continued until there is traffic (detected by automatic sensor) from the following phase.

2.3.3 Traffic-adjusted System

Arahan Teknik (Jalan) 13/87 said that traffic-adjusted system is an advanced

system that using the latest technology to control the network of a few signalised

intersections at one centralised centre. This type of traffic system is more complicated

and complex thus high-skilled technician or operator will be needed to run the system.

Arahan Teknik (Jalan) 13/87 also explained that the controlling and detecting devices

will be placed at the transportation network system so that the centralised control room

can always obtain the real time information. The operation of the signalised intersection

will be modified from time to time in order to suit the current traffic condition.

8

2.4 Traffic Signal Control

Arahan Teknik (Jalan) 13/87 stated that signal control is to provide a safe and

efficient traffic flow through intersections, along routes and in road networks. Arahan

Teknik (Jalan) 13/87 and Garber N. J. and Hoel L. A. (2009) described the primary

purpose of traffic signal control is to assign the right of way for alternate roads or road of

approaches in order to maximize capacity, minimize delay, reduce conflicts, and facilitate

safety by ensuring the orderly and predictable movement of all traffic on the intersection.

Garber N. J. and Hoel L.A. (2009) explained that the signal control may be achieved by

using traffic signals, sign, or marking that regulate, guide, warn, and/or channel traffic.

2.5 Signal Display and Location

Arahan Teknik (Jalan) 13/87 explained the two fundamental principles that must

be carefully considered to serve its intended purpose in directing and regulating traffic

flow that is the conspicuity and clarity. Arahan Teknik (Jalan) 13/87 defined conspicuity

as the signal must not only visible, but must be obvious to the eye and attract attention.

Arahan Teknik (Jalan) 13/87 also defined clarity as the message or direction given can be

easily understood. In other words, the signal must be seen in order for the driver to react

and the required action must be obvious.

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2.6 Signal Display Requirement

According to Arahan Teknik (Jalan) 13/87, For the driver to respond effectively to the

traffic signal, these basic requirements have to be considered.

• The amount of light reaching the driver's eye.

• The position of the signal in the driver's field of view.

• The ratio of the signal in the driver's field of view.

• The ratio of the signal-to-background contrast.

• The amount of competing information sources (visual clutter or "noise").

• The degree to which the appearance of the signal is expected.

• The degree to which the precise location of the signal is known.

• The degree to which the message conform to the driver's knowledge and

expectations.

2. 7 Geometric Design of Signalised Intersections

Generally, Joe G. B. (2005) mentioned about the geometric design of signalised

intersections that covers channelisation principles, number of intersection approaches,

intersection angles, horizontal and vertical alignments, comer radius and curb ramp

designs, detectable warnings, access control, sight distance, pedestrian facilities, and

bicycle facilities. Besides that, Joe G. B. (2005) explained that the geometric design also

includes making evident points of potential conflict in an intersection, particularly those

involving vulnerable road users and offering the approaching road users a clear view of

one another.

10

Joe G. B. (2005) also mentioned that the design influences roadway safety, shapes

the expectations of road users, and defines how to proceed through an intersection.

However, Joe G. B. (2005) proved that the design can facilitate desired vehicle and

pedestrian actions by discouraging undesirable movements, defining appropriate paths for

vehicles, encouraging safe speeds, helping separate points of conflict, facilitating the

movement of high priority traffic flows, providing safe refuge, and offering way-finding

clues for road users.

Joe G. B. (2005) stated that the primary goal of intersection design is to limit the

severity of potential conflicts among road users. Besides, Joe G. B. (2005) also explained

about the geometric design concept that the intersection channelisation that is used to

reduce conflicts employ such techniques as raised, medians to traffic islands to

discourage wrong-way turns and undesirable movements. Furthermore, Joe G. B. (2005)

also described the alternative usage of channelisation techniques such as pavement

marking to delineate desirable vehicle paths.

2.8 Traffic Control and Analysis at Intersections

Mannering, F. L. (2009) described that roadway intersections are a source of great

concern to traffic engineers. Mannering, F. L. (2009) explained that intersections can be

a major source vehicles delays as vehicles yield to avoid conflicts with other vehicles.

Mannering, F. L. (2009) also explained that a poorly timed signal or one that is not

justified can have a negative impact on the operation of the intersection by increasing

vehicle delay, causing a disruption to traffic progression which is adversely impacting the

through movement of traffic, and encouraging the use of routes not intended for through

traffic such as routes through residential neighbourhood.

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2.9 Signalised Intersection

Mannering, F. L. et al. (2009) defined an intersection as an at-grade crossing of

two or more roadways. Joe G. B., (2005) mentioned that signalised intersection is a key

component in improving the safety and efficiency of intersections. A proper design of the

intersection would increase the level of service of a signalised intersection to a better

level. Joe G. B., (2005) explained that traffic engineers need to consider a variety of

elements when designing a system for signalisation at an intersection. Joe G. B., (2005)

said that one factor is the type of control, either pre-timed signal that operates with a

fixed cycle length or an actuated signal that varies the length of the green light based on

traffic demand.

The development of a signal timing plan should address all user needs at a

particular location, including transit vehicles, emergency vehicles, automobiles, and

trucks. In general, the Arahan Teknik Jalan 13/87 recommends that the optimum cycle

lengths/time for conventional, four-legged intersections is between 120 second to 140

second.

Another design element is signal phasing (Joe G. B., 2005). A signal phase is the

interval of time allotted for green, yellow, and red in a traffic movement cycle (Joe G. B.,

2005). Signal phasing is the sequence of individual phases in a cycle that defines the

order in which road users have the right-of-way to move through the intersection (Joe G.

B., 2005).

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2.10 At-grade Intersection Characteristics

AASTHO (2001) introduced four basic elements that enter into design

considerations of at-grade intersections which are the human factors, traffic

considerations, physical elements, and economic factors. However, Jha M.K. et al. (2001)

explained that those mainly affecting alignments are vehicle speeds, vertical alignments

at the intersection that is the differences between an existing road and new road, angle of

the intersection, geometric features like topography of the site and cross sections, design

hourly turning movement with additional lane needed for turning volumes, and sight

distances.

2.11 Capacity of Intersections

The term capacity of an intersection refers to the ability of a roadway to

accommodate traffic (REAM, 2002). It is defined as the maximum number of vehicles

that can pass over a given section of a lane or a roadway during a given time period under

prevailing roadway and traffic conditions (REAM, 2002). Generally, major intersections,

signalised intersections, or unsignalised intersections will determine the overall capacity

and performance of the road network (Arahan Teknik Jalan 11/87, 1987). Significantly,

channelisation and intersection control can control and lessen the volume of crossing or

turning traffic at minor roads which will cause interruptions and capacity reductions

(Arahan Teknik Jalan 11/87, 1987). The capacities of intersections are very important and

to achieve balance, the intersection design should take into account the capacity of the

approach roads (Arahan Teknik Jalan 11/87, 1987).

13

Generally, the capacities of signalized intersections are determined by a long list

of determinants (Xiaoming et al., 2009). According to Xiaoming et al., (2009) mentioned

that the determinants include not only deterministic factors like the geometric and

signalized conditions, but also random effects such as differences in traffic composition,

random driver behaviour, and the resulting random intersections between vehicles.

Arahan Teknik Jalan 13/87 suggested that traffic engmeers must design the

intersection so that the intersection will not be fully utilized till its full capacity. Thus,

engineers must gather all the information from the capacity analysis so that they can

design the intersections based on the given information. The engineers will upgrade the

existing intersections by considering the long queue of the traffic volume during peak

hours. The engineers must design the existing intersections capacity.

2.12 Analysis of Traffic at Signalised Intersections

2.12.1 Saturation Flow Rate

Garber N. J. and Hoel L. A. (2009) defined the saturation flow rate as the

maximum flow rate on the approach or lane group that can go through the intersection

under prevailing traffic and roadway conditions when 100 percent effective green is

available. Garber N. J. and Hoel L. A. (2009) explained that the concept of saturation

flow or saturation flow rate (s) is used to determine the capacity of a lane group. Garber

N. J. and Hoel L.A. (2009) also mentioned that the saturation flow rate is given in units

of veh/h of effective green time.