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.
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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
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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
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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
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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.
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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.
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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).
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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.