SENSITIVITY ANALYSIS OF MALAYSIAN HIGHWAY CAPACITY
MANUAL FOR UNSIGNALISED INTERSECTIONS
IZZIAN BINTI IZZUDDIN
This Thesis Is Propose To
Faculty of Engineering, University Malaysia Sarawak
For Fulfillment of the Requirements for Bestowal
The Degree of Bachelor of Engineering with Honours
(Civil Engineering)
2009
This final year project attached here:
Title : SENSITIVITY ANALYSIS OF MALAYSIAN
HIGHWAY CAPACITY MANUAL FOR
UNSIGNALISED INTERSECTIONS
Prepared by : IZZIAN BINTI IZZUDDIN
Matric No. : 14172
Is hereby read and approved by:
__________________________ ___________________
Prof. Dr. Wan Hashim Wan Ibrahim Date
Project Supervisor
UNIVERSITI MALAYSIA SARAWAK
BORANG PENGESAHAN STATUS TESIS
JUDUL: SENSITIVITY ANALYSIS OF MALAYSIAN HIGHWAY CAPACITY MANUAL
FOR UNSIGNALISED INTERSECTIONS
SESI PENGAJIAN: 2008-2009
Saya IZZIAN BINTI IZZUDDIN
(HURUF BESAR)
mengaku membenarkan tesis * ini disimpan di Pusat Khidmat Maklumat Akademik,
Universiti Malaysia Sarawak dengan syarat-syarat kegunaan seperti berikut:
1. Tesis adalah hakmilik Universiti Malaysia Sarawak.
2. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat
salinan untuk tujuan pengajian sahaja.
3. Membuat pendigitan untuk membangunkan Pangkalan Data Kandungan Tempatan.
4. Pusat Khidmat Maklumat Akademik, Universiti Malaysia Sarawak dibenarkan membuat
salinan tesis ini sebagai bahan pertukaran antara institusi pengajian tinggi.
5. ** Sila tandakan ( √ ) di kotak yang berkenaan
SULIT (Mengandungi maklumat yang berdarjah keselamatan atau kepentingan
Malaysia seperti yang termaktub di dalam AKTA RAHSIA RASMI 1972).
TERHAD (Mengandungi maklumat TERHAD yang telah ditentukan oleh
organisasi/badan di mana penyelidikan dijalankan).
√ TIDAK TERHAD
Disahkan oleh
___________________________ ____________________________
(TANDATANGAN PENULIS) (TANDATANGAN PENYELIA)
Alamat Tetap: 474 Kg Wakaf Mek Zainab, PROF. DR. WAN HASHIM WAN IBRAHIM
15300 Kota Bharu, (Nama Penyelia)
Kelantan Darul Naim
Tarikh: 1 JUN 2009 Tarikh: 5 JUN 2009
Catatan: * Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah, Sarjana dan
Sarjana Muda.
** Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak
berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis
ini perlu dikelaskan sebagai SULIT atau TERHAD.
To Mama & Papa
With Lots of Love
iii
ACKNOWLEDGEMENT
In the name of Allah, all Praise is due to Him, the Sustainer of the Heavens and
Earth and all that is within it and may His Blessings be upon the Prophet Muhammad,
peace be upon him. Alhamdulillah, by the grace of Allah and without His permission,
this study may not be completed.
I would like to offer my heartfelt thanks to all that involve in the completion of
this thesis especially to my supervisor, Professor Dr. Wan Hashim Wan Ibrahim for his
guidance and valuable knowledge for this study. I would also like to thank the
technicians of Highway and Traffic Laboratory, Mr. Saiful Edi and Mr. Ar-Rasyidin.
Not forgetting my friends for giving me help and support throughout the study
especially to Siti Zarini, Mohd Rozaidi, Mohd Zuki and Mohammad Khalis Afham.
Thank you so much.
Lastly, no word can ever express my deepest gratitude to my parents. I can only
say a world of thanks to your prayers, patience and untiring support in every way.
Thanks Papa and Mama! My gratitude is also extended to my sisters, Izzlin and Izznie,
for their supports and motivations. Thanks again to all, may Allah grant you with many
good deed. Ameen!
iv
ABSTRACT
Unsignalised intersections play an important role in determining capacity of
road network. Two major parameters used in unsignalised intersection analysis are
critical gap and follow-up time. There are several factors affecting the critical gap
and the follow-up time such as vehicle composition, intersection geometry, major
street traffic volume, minor street delay, minor stream approach grade, and others. In
this research, the critical gap and the follow-up time were analyzed based on vehicle
type, specifically passenger car and motorcycle. Critical gap estimations were based
on the Maximum Likelihood method. These two major factors will be used to
estimate the level of service and capacity of unsignalised intersections. Malaysian
Highway Capacity Manual (MHCM) was produced based on the traffic condition in
West Malaysia. The study is to find out the application of MHCM in Sarawak.
Sensitivity analysis is being carried out by using MHCM 2006.
v
ABSTRAK
Persimpangan keutamaan memainkan peranan penting dalam menentukan
kapasiti jaringan jalan. Dua parameter utama yang digunakan dalam analisis
persimpangan keutamaan adalah sela kritikal dan masa kemajuan. Terdapat beberapa
faktor yang mempengaruhi sela kritikal dan masa kemajuan seperti komposisi
kenderaan, geometri persimpangan, isipadu lalu lintas utama, kelengahan jalan
minor, kecerunan jalan minor dan sebagainya. Dalam kajian ini, sela kritikal dan
masa kemajuan dianalisis berdasarkan kenderaan penumpang dan motorsikal.
Anggaran sela kritikal adalah berdasarkan kaedah Kebarangkalian Maksimum. Dua
faktor utama ini akan digunakan untuk menganggarkan tahap perkhidmatan dan
kapasiti bagi persimpangan keutamaan. Panduan Kapasiti Lebuhraya di Malaysia
(MHCM) diterbitkan berdasarkan keadaan trafik di Semenanjung Malaysia. Kajian
ini adalah untuk mengetahui kebolehan MHCM untuk diaplikasikan di Sarawak.
Analisis kesensitifan dijalankan merujuk kepada MHCM 2006.
vi
TABLE OF CONTENT
Page
Acknowledgement iii
Abstract iv
Abstrak v
Table of Content vi
List of Table ix
List of Figure xi
List of Abbreviation xiii
Chapter 1 INTRODUCTION
1.1 Introduction 1
1.2 Problem Statement 3
1.3 Objectives of the Study 3
1.4 Scope of the Study 4
1.5 Outline of the Report 6
Chapter 2 LITERATURE REVIEW
2.1 Introduction 7
2.2 Unsignalised Intersection 8
2.3 Critical Gap Estimation 9
2.3.1 Maximum Likelihood Method 10
2.4 Follow-Up Time Estimation 12
vii
2.5 Review of Highway Capacity Manual
2.5.1 Malaysian Highway Capacity Manual 2006 13
2.5.2 US Highway Capacity Manual 2000 14
2.5.3 Indonesian Highway Capacity Manual 1993 14
Chapter 3 METHODOLOGY
3.1 Introduction 17
3.2 Vehicle Movement at Unsignalised Intersections 19
3.3 Conflict Area at Unsignalised Intersections 20
3.4 Left Turn Movement from Minor Stream 21
3.5 Site Selection 22
3.5.1 Equipment 23
3.6 Field Observation Method 25
3.7 Gap Acceptance Reduction 26
3.7.1 Maximum Likelihood Method 26
3.8 Estimation of Critical Gap and Follow-Up Time 28
Chapter 4 DATA ANALYSIS AND DISCUSSION
4.1 Data Collection and Analysis 30
4.2 Estimation of Critical Gap 39
4.3 Sensitivity Analysis 45
4.3.1 Effect of Critical Gap 45
4.3.1.1 Movement Capacity 47
4.3.2 Effect of Follow-Up Time 48
4.3.2.1 Movement Capacity 51
viii
4.4 Comparison of Critical Gap and Follow-Up Time
Values with Other Studies 53
Chapter 5 CONCLUSION AND RECOMMENDATION
5.1 Summary 56
5.1.1 Everrise Unsignalised Intersection 57
5.1.2 J & J Cafeteria Unsignalised Intersection 58
5.2 Conclusion 59
5.3 Recommendation 60
References 62
Appendix A Data Analysis using Maximum Likelihood Method 65
Appendix B Cumulative Distribution Function of Passenger Car’s and
Motorcycle’s Gap Acceptance 82
Appendix C Data Collection 95
Appendix D Sensitivity Analysis 102
Appendix E Vehicle Composition Data 105
ix
LIST OF TABLE
Table Title Page
4.1 Vehicle composition data for AM Peak at Everrise unsignalised 33
intersection (Kuching to Kota Samarahan)
4.2 Vehicle composition data for AM Peak at Everrise unsignalised 34
intersection (Kuching to Desa Ilmu)
4.3 Vehicle composition data for AM Peak at Everrise unsignalised 34
intersection (Desa Ilmu to Kota Samarahan)
4.4 Vehicle composition data for AM Peak at Everrise unsignalised 35
intersection (Desa Ilmu to Kuching)
4.5 Vehicle composition data for AM Peak at Everrise unsignalised 35
intersection (Kota Samarahan to Kuching)
4.6 Vehicle composition data for AM Peak at Everrise unsignalised 35
intersection (Kota Samarahan to Desa Ilmu)
4.7 Data collection for traffic flow at Everrise unsignalised
intersection (veh/hr) 36
4.8 Data collection for traffic flow at J & J Cafeteria unsignalised
intersection (veh/hr) 36
4.9 Data analysis for critical gap estimation 41
4.10 Parameters for critical gap for Everrise unsignalised
intersection (Sanik, 2006) 46
4.11 Variation of critical gap values 46
x
4.12 Sensitivity analysis of movement capacity with respect to critical
gap value for Everrise unsignalised intersection 47
4.13 Parameters for follow-up time for Everrise unsignalised
intersection (Sanik, 2006) 49
4.14 Variation of follow-up time values 50
4.15 Sensitivity analysis of movement capacity with respect to
follow-up time value for Everrise unsignalised intersection 51
4.16 Comparison of critical gap values using Maximum Likelihood
method with other studies 53
4.17 Comparison of follow-up time values with other studies 54
4.18 Level of service for Everrise and J & J Cafeteria unsignalised
intersections (for left turn movement from minor stream only) 55
5.1 Statistical summary of data observed for Everrise unsignalised
intersection 57
5.2 Statistical summary of data observed for J & J Cafeteria
unsignalised intersection 58
5.3 Suggested critical gap values for Sarawak road condition (sec) 59
5.4 Suggested follow-up time values for Sarawak road
condition (sec) 59
xi
LIST OF FIGURE
Table Title Page
1.1 The location of the study area 4
1.2 Illustration of a typical T-junction in Malaysia (MHCM, 2006) 5
2.1 Capacity calculation flow chart (IHCM, 1993) 16
3.1 Outline of the study 18
3.2 Vehicle movement at unsignalised intersections (Asmi, 2003) 19
3.3 Conflict area at unsignalised intersections (Brilon et al., 1999) 20
3.4 Gap measurement for left turn movement from minor stream
(Asmi, 2003) 21
3.5 Photo of unsignalised intersections at Everrise 22
3.6 Photo of unsignalised intersections at J & J Cafeteria 23
3.7 Photo of video camera 24
3.8 Photo of walking wheel 24
3.9 Photo of stop watch 24
3.10 A typical unsignalised T-junction 25
3.11 Flow chart of Maximum Likelihood method procedure
(Asmi, 2003) 27
3.12 Flow chart for follow-up time determination (Asmi, 2003) 29
4.1 Geometric layout of Everrise unsignalised intersection 31
4.2 Geometric layout of J & J Cafeteria unsignalised intersection 31
4.3 The direction of traffic flow of both unsignalised intersection 32
xii
4.4 Traffic volume (pcu/hr) for AM Peak Hour (7 – 8 am) 37
4.5 Traffic volume (pcu/hr) for Off Peak Hour (3 – 4 pm) 38
4.6 Traffic volume (pcu/hr) for PM Peak Hour (5 – 6 pm) 38
4.7 Cumulative function of passenger car’s gap acceptance by
Maximum Likelihood method 43
4.8 Sensitivity analysis of movement capacity with respect to critical
gap value for Everrise unsignalised intersection 48
4.9 Sensitivity analysis of movement capacity with respect to
follow-up time value for Everrise unsignalised intersection 52
5.1 Illustration of Everrise unsignalised intersection 57
5.2 Illustration of J & J unsignalised intersection 58
xiii
LIST OF ABBREVIATION
HCM - Highway Capacity Manual
LOS - Level of Service
MHCM - Malaysian Highway Capacity Manual
ITS - Intelligent Transport System
ROW - Right of Way
USHCM - United States Highway Capacity Manual
IHCM - Indonesia Highway Capacity Manual
MajRT - Right Turn Movement from Major Stream
MinLT - Left Turn Movement from Minor Stream
MinRT - Right Turn Movement from Minor Stream
TRB - Transportation Research Board
1
CHAPTER 1
INTRODUCTION
1.1 Introduction
Nowadays, Malaysia owns modern highway infrastructures and is among the
best highway in Asia Tenggara. However, according to Polis DiRaja Malaysia Report
for year 1990 - 1995, the accident rates in Malaysia are increasing and need to be
concerned about. Besides, traffic congestion and delay is also increasing due to
additional number of vehicles on the road. Therefore, a systematic road control needs
to be taken by the responsible agencies to reduce traffic congestions.
Unsignalised intersection is a common type of intersection used to control
traffic movement. They play an important role in determining overall capacity of
road networks. A poorly operating unsignalised intersection may affect adjacent
signalized intersection or an Intelligent Transport System. Therefore, it is extremely
important to make sure that the intersection is designed appropriately to prevent under
or over designed of transportation facilities.
2
For an unsignalised intersection, the driver alone must decide when it is safe to
enter the intersection as there is only stop sign to help them, unlike the signalised
intersections. The driver looks for a safe chance or gap in the traffic to enter the flow.
This method is called as gap acceptance. Gaps are measured in the unit of time and
the time difference between the front bumper of one vehicle to the front bumper of the
following vehicle is defined as headway. At unsignalised intersections, there are other
vehicles that will have priority over the driver trying to enter the traffic stream and the
driver must yield to these drivers.
Critical gap and follow-up time are two major parameters for various gap
acceptance capacity models. The values of these two parameters significantly affect
the final capacity result, therefore, it is important to accurately measure these two
parameters based on certain traffic and intersection conditions. Based on the study by
Asmi (2003), the 1997 update to the Highway Capacity Manual (HCM) included a
new set of critical gap and follow-up time values calibrated based on the U.S.
highway conditions. The newly recommended set of critical gap and follow-up time
values formed the basis for the procedures for two-way stop-controlled intersections
included in the 1997 update to the HCM and the 2000 HCM. It can be concluded that
these two parameters are the major factors to estimate the level of service (LOS) and
capacity of unsignalised intersections.
3
1.2 Problem Statement
Malaysia had produced its own Highway Capacity Manual in 2006 and it is
known as Malaysian Highway Capacity Manual (MHCM). MHCM study was based
on the traffic condition strictly in West Malaysia. Several locations such as Kuala
Lumpur, Ipoh, Malacca and Penang were taken into consideration to bring out the
best result.
Driver’s behavior is different at a different location. With a low traffic volume
and many one-way routes, Sarawak drivers create their own style of driving. Critical
gap and follow up time may be differing due to this condition. Therefore, this study is
to determine whether the MHCM is applicable to design unsignalised intersections in
Sarawak.
1.3 Objectives of the Study
The objectives of this study are as follows:
a) To determine the critical gap by using the Maximum Likelihood method
and follow-up time at unsignalised intersections.
b) To carry out sensitivity analysis for unsignalised intersections using
Malaysian Highway Capacity Manual 2006.
4
1.4 Scope of the Study
The study will be carried out in Desa Ilmu, Kota Samarahan, Sarawak,
Malaysia. Two unsignalised intersections have been selected as the study areas due to
limited time and resources to get the data and they are situated near the Universiti
Malaysia Sarawak. Figure 1.1 shows the layout plan of Desa Ilmu with junctions
observed are marked with red circle.
Figure 1.1: The location of the study area
5
Figure 1.2 shows the illustration of a typical T-junction in Malaysia and the
rank of the movements. Ranks of movement are the discipline of the movements at T-
junction which have the right of way according to the priority. In this study, only one
movement is analysed. The movement is represented by number 9 which is left turn
from minor road (LTMin).
Figure 1.2: Illustration of a typical T-junction in Malaysia (MHCM, 2006)
STOP
7 9
4
5
3
2
Rank Traffic stream
1 2, 3, 2 4, 9
3 7 4 7
6
1.5 Outline of the Report
The first chapter of this study gives a general introduction of the overall study
content and the general background of parameters involved in the analysis of
unsignalised intersection. The second chapter reviews the relevant literatures related
to gap acceptance parameter and follow up time studies. Consequently, Chapter 3
discusses the study methodology carried out for this study. Chapter 4 describes the
analysis of the data and discuss the findings. Finally, Chapter 5 concludes and gives
some recommendation for this study.
7
CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
Unsignalised intersection is the common type of intersections used to control
traffic movements. They play an important role in the control of the traffic network
system. According to Wua et al. (2005), the study of unsignalised intersection is
actually the base of other intersections’ study. The interaction between vehicles on
different lanes, and the effects of different traffic policies on the traffic volume are
not only of scientific significance on the development of traffic theory, but also of
guiding importance for establishing suitable traffic policies.
The theory of the operation of unsignalised intersections is fundamental to
many elements of theory used for other intersections. Unsignalised intersections do
play an important part in the control of traffic flow in a network even though their
capacities may be lower than other intersection types. A poorly operating
unsignalised intersection may affect a signalised network or operation of an
Intelligent Transport System (ITS) (MHCM, 2006).
8
In Malaysia, majority of the unsignalised intersections is the T-intersection.
Majority of the 4-way unsignalised intersections are converted to signalised
intersection. T-junction can be described as an intersection where two roads meet
(whether or not at right angles) and one of the road ends. It may include an
intersection where more than two roads meet but only one continues.
In this study, we are focusing on the unsignalised T-junction to obtain the
critical gap and follow-up time for vehicles in Sarawak.
2.2 Unsignalised Intersections
According to Wohl and Martin (1967), unsignalised intersections can be
classified into three categories:
1. Uncontrolled intersections
2. Priority intersections
3. Space sharing intersections
An uncontrolled intersection is a road intersection where no traffic lights or
signs are used to indicate the right-of-way (ROW). At most locations, uncontrolled
intersections are unmarked. Traffic on the terminating road must give way to traffic
on the continuing road. They are found in either residential neighborhoods or in rural
areas.
9
At priority intersection, the minor road traffic gives way to that on the main
road and only enters the main road traffic stream during gaps. Unlike the
uncontrolled intersection, priority intersection normally being controlled by Stop or
Give Way signs and markings on the minor road. The advantage of these
intersections is all the vehicles on the main road are not being delayed.
There are four types of priority intersections:
1. Simply priority T-intersections
2. Ghost island T-intersections
3. T-intersections with single dualling
4. T-intersections with dual two-lane rural roads
Space sharing at an intersection is intended to permit fully equal priority and
continuous movement for all intersecting vehicle flows at the roundabout and
weaving areas. The priority at space sharing intersection is not generally assigned to
any specific traffic stream. Each traffic stream crosses at a rather low traffic speed
and it is normally not necessary to stop.
2.3 Critical Gap Estimation
The critical gap, tc is the minimum travel time interval between the vehicles
of the major stream that is necessary for the vehicles in the minor stream to enter the
conflict area (MHCM, 2006).