Recommendations to reduce the container truck congestion in entrance gates at a port of viconship joint stock conpany greenport terminal

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MINISTRY OF TRANSPORTATION MINISTRY OF EDUCATION & TRAINING
VIETNAM MARITIME UNIVERSITY
STUDENT NAME: TO DINH BACH
DISSERTATION
GLOBAL STUDIES AND MARITIME AFFAIRS
RECOMMENDATIONS TO REDUCE THE CONTAINER TRUCK
CONGESTION IN ENTRANCE GATES AT A PORT OF VICONSHIP
JOINT STOCK CONPANY- GREENPORT TERMINAL
HAI PHONG – 2015
MINISTRY OF TRANSPORTATION MINISTRY OF EDUCATION & TRAINING
VIETNAM MARITIME UNIVERSITY
STUDENT NAME: TO DINH BACH
CLASS: GMA 02
DISSERTATION
GLOBAL STUDIES AND MARITIME AFFAIRS
RECOMMENDATIONS TO REDUCE THE CONTAINER TRUCK
CONGESTION IN ENTRANCE GATES AT A PORT OF VICONSHIP
JOINT STOCK CONPANY- GREENPORT TERMINAL
Supervisor: Vuong Thu Giang
Division: Basic economic
Faculty: Global Studies and Maritime Affairs
HAI PHONG – 2015
Recommendation to reduce container truck congestion in entrance gates at a port of VICONSHIP
joint stock company- Greenport terminal
PREFACE
Purpose of the paper is to evaluate situation of container truck congestion in
terminal gates at a port of VICONSHIP joint stock company- Greenport terminal.
Then, recommendations are suggested to reduce container truck congestion in
Greenport terminal gates.
There are five main parts in this paper:
1. Introduction
2. Chapter 1: Literature review
3. Chapter 2: Situation of container truck congestion in Greenport terminal gates
4. Chapter 3: Recommendations to reduce the truck congestion in Greenport
terminal gates
5. Conclusion
I declare that this report is my own unaided work. It has not been
submitted before.
If violated, I am solely responsible for and bear the punishments of the
Institution and University.
Student Name and Signature
To Dinh Bach
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Recommendation to reduce container truck congestion in entrance gates at a port of VICONSHIP
joint stock company- Greenport terminal
ABSTRACT
Vietnam is a favorable natural country having 3200 km sea-way. So the
development of maritime transports will bring benefits for country, especially in
container transportation. There are 72% container level approximately imported and
exported in South Vietnam ports and 26% in North ports, Vietnam ports could
compete to another region such as Singapore, Hong Kong or Busan (Thai Van Vinh,
2007). In fact, many ports are facing heavy truck congestion in the terminal, which
leads to longer truck waiting time and lower operation efficiency (Xiaoju Zhang,
et.al, 2013). Although Vietnam built so many large container ports, container truck
congestion still occur in major terminal gate because volume of container exceeds in
rush period.
Then, what is the cause of the congestion problem at the port container and
how to resolve this situation? The research figures out the underlying cause of the
problem and offers some solutions to remedy the situation, as well as to develop
Vietnam's seaports.
The research will contribute some positive solution to address the immediate
situation contributing to Vietnam's seaport grows and brings many benefits not only
for the state but also for the whole society.
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Recommendation to reduce container truck congestion in entrance gates at a port of VICONSHIP
joint stock company- Greenport terminal
ACKNOWLEGEMENT
First of all, I would like to thank Ms. Phuong Anh, master of accounting
manager, who gave me a chance to internship in Greenport terminal and gave a hand
to help me have information and important statistics. I would like to thank security
and related employee who help me to successfully finish our project without any
interrupted. I also want to thank my instructor- Mrs. Nguyen Thi Le Hang who
supervised my industrial project that is modeling and simulation material handling
system in container terminal and who gave me this valuable chance to work with her
for a small period. I also want to thanks Huynh Viet and Duc Thuan who make long
conversations to answer for many questions and spend time to introduce
departments of Greenport. Finally, I would like to thank everyone who helped me in
direct and indirect ways during period of project.
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Recommendation to reduce container truck congestion in entrance gates at a port of VICONSHIP
joint stock company- Greenport terminal
TABLE OF CONTENTS
PREFACE........................................................................................................................................1
ABSTRACT.....................................................................................................................................2
ACKNOWLEGEMENT.................................................................................................................3
LIST OF ABBREVIATIONS.........................................................................................................8
LIST OF TABLES..........................................................................................................................9
LIST OF FIGURES......................................................................................................................10
INTRODUCTION.........................................................................................................................11
1. Introduction...........................................................................................................................11
2. Methodology..........................................................................................................................11
3. Research scope.......................................................................................................................11
CHAPTER I: LITERATURE REVIEW....................................................................................12
1.1. Seaport................................................................................................................................12
1.1.1. Definition of Seaport....................................................................................................12
1.1.2. Functions of Seaport....................................................................................................12
1.1.2.1. Traffic function.........................................................................................................12
1.1.2.2. Merchant function.....................................................................................................12
1.1.2.3. Industrial function....................................................................................................13
1.1.3. Classification of Seaport..............................................................................................13
1.2. Container terminal.............................................................................................................15
1.2.1. Definition of container terminal..................................................................................15
1.2.2. Functions of container terminal..................................................................................15
1.3. Terminal gates....................................................................................................................15
1.3.1. Terminal layout gates...................................................................................................16
1.3.2. Several model simulations applied in terminal gates...................................................16
1.4. Congestion Overview..........................................................................................................17
1.4.1. Definition of congestion...............................................................................................17
1.4.2. Types of congestion......................................................................................................20
1.4.3. Congestion Causes.......................................................................................................22
1.4.4. Approaching to Congestion identification...................................................................23
1.4.5. Quantitative measures of Congestion Identification...................................................23
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Recommendation to reduce container truck congestion in entrance gates at a port of VICONSHIP
joint stock company- Greenport terminal
CHAPTER II: SITUATION OF CONTAINER TRUCK CONGESTION IN ENTRANCE
GATES AT A PORT OF VICONSHIP JOINT STOCK COMPANY- GREENPORT
TERMINAL...................................................................................................................................25
2.1. Greenport introduction......................................................................................................25
2.1.1. General information.....................................................................................................25
2.1.2. Foundation History of VICONSHIP and Greenport- Subsidiaries............................26
2.1.3. General terminal layout:..............................................................................................27
2.1.4. Organization and personnel.........................................................................................28
2.1.5. Main services................................................................................................................29
2.1.5.1. Berths.........................................................................................................................29
2.1.5.2. CFS Warehouses.......................................................................................................30
2.1.5.3. Container yards.........................................................................................................31
2.1.6. Greenport entrance gate facilities................................................................................31
2.1.7. Business operations report of Greenport:....................................................................33
2.2. General Greenport congestion situation...........................................................................35
2.2.1. Greenport entrance gates situation..............................................................................36
2.2.2. Greenport congestion identification by quantitative measures...................................38
2.2.2.1. Measurement specification 1 (Secs/mile lost due to congestion)..............................38
2.2.2.2. Measurement specification 4 (% of time spent in jams)...........................................39
2.2.3. Greenport congestion causes........................................................................................40
2.2.4. Consequence of Congestion.........................................................................................41
2.2.4.1. In term of enterprise/ terminal..................................................................................41
2.2.4.2. In term of social.........................................................................................................42
2.2.4.3. In term of environment.............................................................................................42
CHAPTER III: RECOMMENDATIONS TO REDUCE CONTAINER TRUCK
CONGESTION IN ENTRANCE GATES AT A PORT OF VICONSHIP JOINT STOCK
COMPANY- GREENPORT TERMINAL..................................................................................43
3.1. Recommendation of technology.........................................................................................43
3.1.1. Truck appointment system (TAS).................................................................................43
3.1.1.1. Goals of TAS..............................................................................................................43
3.1.1.2. TAS process...............................................................................................................43
3.1.1.3. TAS strengths and weaknesses..................................................................................45
3.1.2. OCR (optical character recognition) gate automation................................................46
3.1.2.1. Truck OCR (optical character recognition) camera portal system...........................47
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3.1.2.2. Operator consoles......................................................................................................48
3.1.2.3. Truck-driver self-service kiosks................................................................................48
3.1.2.4. Brief process of OCR entrance gate automation......................................................49
3.1.2.5. OCR gate automation strengths................................................................................50
3.2. Recommendation of infrastructural..................................................................................50
3.2.1. Road extension (RE)....................................................................................................50
3.2.2. New subsidiary- VIP Greenport...................................................................................51
APPENDICES...............................................................................................................................53
1. Business Process Modeling of Automatic gate.........................................................53
References......................................................................................................................................54
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LIST OF ABBREVIATIONS
LCL: Less than Container Load
CFS: Container freight station
CCTV: Closed-circuit television
VOCs: Volatile Organic Compounds
TAS: Truck appointment system
HDC: Harbor development commission
OCR: Optical character recognition
LPR: Location plates reader
ISO: International organization for standardization
TOS: Terminal operating system
LCD: Liquid crystal display
VoIP: Voice over IP
IP: Internet Protocol
RE: Road extension
EDI: Electronic Data Interchange
PL-TOS: Port logics-Terminal Operation System
IAS: Individual appointment systems
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LIST OF TABLES
Table 1.1: Alternate definition of congestion..........................................................17
Table 1.2: Summary of types of congestion............................................................19
Table 1.3: Alternative congestion measures to assess user acceptability................22
Table 2.4: Greenport business operation report......................................................33
Table 2.5: Congestion identification as Qualitative measures.................................35
Table 2.6: The First Measurement specification (seconds/mile).............................37
Table 2.7: The First Measurement specification (minutes/meter)...........................38
Table 2.8: Congestion identification as the first Measurement specification..........38
Table 2.9: Congestion identification as the second Measurement specification.....39
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joint stock company- Greenport terminal
LIST OF FIGURES
Figure 1.1: Terminal layout gates...........................................................................15
Figure 2.2: Greenport layout...................................................................................26
Figure 2.3: Management organization of VICONSHIP..........................................28
Figure 2.4: Greenport berths...................................................................................29
Figure 2.5: CFS warehouses ..................................................................................29
Figure 2.6: Greenport Container yards....................................................................30
Figure 2.7: Greenport entrance gates......................................................................31
Figure 2.8: Greenport CCTV camera......................................................................31
Figure 2.9: Greenport weighting stations................................................................32
Figure 2.10: Business operation chart of Greenport................................................34
Figure 2.11: Researching Location- Greenport Entrance Gates............................. 35
Figure 2.12: Road leading to Greenport entrance gates..........................................36
Figure 3.13: TAS process ......................................................................................43
Figure 3.14: Queuing theory simulation.................................................................44
Figure 3.15: Truck OCR camera portal...................................................................46
Figure 3.16: Operator console in gate automation project .....................................47
Figure 3.17: Truck-driver self-service kiosks ........................................................48
Figure 3.18: Kiosk system......................................................................................48
Figure 3.19: Process of OCR gates automation......................................................49
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INTRODUCTION
1. Introduction
The gate system on container terminals is the operation channel for trucks to
carry containers to move into or out of the container yard. With the rapid
development of maritime logistics, the demand improvement of the container
terminals gate system is becoming higher and higher. If the planning on the
configuration of gate system such as the number of truck lanes is unreasonable, the
congestion by trucks which is waiting and queuing outside the terminal gate
becomes quite serious in the rush hours and it will influence the whole service
performance of the container terminal. Therefore, it is necessary to carry out the
feasible planning on the terminal gate. However the construction cost ratios of
terminal gates is far lower and as the operation performance of the gate system does
not bring the direct punishment charges so the planning on the terminal gate system
has been not considered. So far, researches on planning of container terminals
focused mainly on the gate system.
2. Methodology
The paper is conducted by using combination of methodologies namely
analytical, statistical, logical methods
- Analytical method: Analyze figures and date related to company and
process.
- Statistical method: Collect and research the information about data.
- Logical method: Summary and point out the situation of the process and
recommend solutions.
3. Research scope
Actually, the performance of the gate system plays an important role in
enhancement of service quality of ports. Congestion in front of gate occurs
frequently not only in Vietnam terminal but also in most of terminal in over the
world. However, the paper only focuses on researching Greenport gate operation
and congestion phenomena.
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CHAPTER I: LITERATURE REVIEW
1.1. Seaport
1.1.1. Definition of Seaport
The concept of ports associated with the development of the maritime
industry. Previously seaport is only storm shelter of boats. Nowadays development
of the maritime industry led to the definition of seaports as well detailed and wider.
Dr. Jean-Paul Rodrigue (1998-2015) indicated that “Ports are points of convergence
between two geographical domains of freight circulation (sometimes passengers);
the land and maritime domains.
The term port comes from the Latin portus, which means gate or gateway
(Jean-Paul Rodrigue, 1998-2015). Historically, ports which are appeared as safe
harbors for fishing have convenient locations became trade hubs, many of which of
free access and designed to protect trade. They became link of urbanization with
many becoming the first port cities playing an important role in the economic
welfare. Today, the most important cities in the world own their port location. In
article of Jean-Paul Rodrigue (1998-2015): “The port is a multidimensional entity at
start anchored within geography, but also dependent on its operations, governance
structure and embedded within supply chains”.
1.1.2. Functions of Seaport
1.1.2.1. Traffic function
In the new function of seaport article of I. Jakomin (2002), the underlying
function of a port is the traffic function. Without it, the port operations would die
away. To cope with the traffic function, the port needs:
-Sufficient capacities, comprising adequate seaport infrastructure and
superstructure
-Good traffic connections with the hinterland
-Good maritime connections
The entire potential of a seaport and its optimal performing of the traffic
functions can only be achieved by matching seaport capacities, transportation
potential of the land infrastructure, and an adequate number of lines and services.
1.1.2.2. Merchant function
In ports, there is a big concentration of goods for the national requirements,
as well as for other countries without access to the sea. The merchant function of a
seaport depends on its traffic function. I. Jakomin (December 12th, 2002) said that a
seaport satisfied the commercial function needs:
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joint stock company- Greenport terminal
- Good land and sea connections
- Concentration of goods in the seaport area
- Adequate storage capacities
In the seaport, the merchant functions include:
- The purchase and sale of goods
- Additional services to the goods, adding to the value thereof
A visible and more elementary form of the merchant function is the purchase
and sale of goods in the seaport area. Various forms of free trade zones grant the
necessary potential for the development of the merchant role of seaports.
1.1.2.3. Industrial function
After the World War II, the industrial activities were introduced in seaports.
The first industrial branches in seaports were shipbuilding and naval equipment
manufacture. These were followed by oil refineries, chemical industries, cement
works and production of fertilizers later on. Today, large international seaports of
world importance support the development of industrial zones and various customs
facilities which allow them to be competitive in the world market. Large industrial
complexes have been built in numerous international seaports, such as in Rotterdam,
Antwerp, the area of Le Havre-Rouen, Marseilles-La Fos-Lyon, Venice-Mestre
(Porta Marghera).
The concentration of industry in seaports offers numerous economic
advantages, and in particular:
- Increases the turnover and provides employment
- Facilitates and furthers the inclusion of the country in international
exchange
- Improves the competitive potential of the industries based in seaports in
comparison with the industry located inland
The underlying precondition for an adequate industrial function in a seaport
is its satisfactory traffic function. Today, industrial seaports or seaport zones with all
the basic facilities for efficient performance are planned already at the time of
construction of new seaports.
1.1.3. Classification of Seaport
Features of attractive port areas, including the criteria in terms of size,
population, type of urban, economic, industrial, maritime services and transport
infrastructure connecting seaports; The role, function and influence of ports for
economic development - local economic development, inter-regional or country;
The size and capabilities of the port, including the criteria for the output of goods
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and cargo through the port; the total length of the harbor, tonnage received at the
present time and as planned; Trends in construction which investments to develop
port and avoid spreading, defined in Article 59 of Vietnam Maritime Code
(http://www.moj.gov.vn/vbpq/Lists/Vn%20bn%20php%20lut/View_Detail.aspx?
ItemID=18150). Port is divided into 3 main types:
Port Type I is particularly important seaport catering mainly for economic
development of the country or inter-regional. Port Type I served as gateway ports or
international transit port, serving the economic development - the country's society
is denoted seaport type IA;
Port Type II is an important sea port mainly served for economic
development of regions and localities;
Port Type III is seaport primarily used exclusively for the operation of the
business.
In terms of the freight handled, ports can be classified in two categories;
monofunctional ports and polyfunctional ports.
Firstly, monofunctional ports transit a limited array of commodities, most
often dry or liquid bulks (raw materials). The oil ports of the Persian Gulf or the
mineral ports of Australia, Africa and in some measure of Canada are
monofunctional ports. They have specialized piers designed to handle specific
commodities and where the flows a commonly outbound, implying that they are
usually load centers.
Secondly, polyfunctional ports are vast harbors where several transshipment
and industrial activities are present. They have a variety of specialized and general
cargo piers linked to a wide variety of modes that can include containers, bulk cargo
or raw materials.
According to the logistic and supply chain documents, port is classified into
many terms. In term of basic functions of seaports including type: Commercial port,
passenger port, industrial port, fishing ports, military ports.
In term of operators: general port and specialized ports.
In term of nature: natural port and artificial port.
In term of technical nature in the port construction: Close port and open
ports.
In term of the scope of port management: National port, public port and
private port.
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1.2. Container terminal
1.2.1. Definition of container terminal
A container terminal is a place where containers arrive by ocean vessels are
transferred to inland carriers, such as trucks, trains, or canal barges and vice verse
(Asmy sheriff, Container terminal analysis, 2008). Generally, a terminal is a facility
where cargo containers are transshipped between different transport vehicles, for
onward transportation. The transshipment may be between ships and land vehicles,
for example trains or trucks, in which case the terminal is described as a maritime
terminal. Alternatively the transshipment may be between land vehicles, typically
between train and truck, in which case the terminal is described as an inland
terminal.
1.2.2. Functions of container terminal
There are 4 main functions of maritime terminal: receiving, storage, staging,
and loading for both import (entering the terminal by sea and usually leaving by
land modes) and export (usually entering the terminal by land and leaving by sea
modes) containers (James E. deMin, Gerard O’Neill, May 2012). Receiving
involves container arrival at the terminal, either as an import or export, recording its
arrival, retrieving relevant logistics data and adding it to the current inventory.
- Storage is the function of placing the container in a known and recorded
location so it may be retrieved when it is needed.
- Staging is the function of preparing a container to leave the terminal. In
other words the containers that are to be exported are identified and organized so as
to optimize the loading process. Import containers follow similar processes,
although staging is not always performed. An exception is a group of containers
leaving the terminal via rail.
- Finally, the loading function involves placing the correct container on the
ship, truck, or other mode of transportation. In this work the emphasis will be put on
internal logistics chain of container terminal (i.e. vessel-truck-yard and opposite
direction respectively).
1.3. Terminal gates
Terminal gates which are points of entry stack area or exit terminal separate
between terminal and outsight. The gate system on container terminals is the
operation channel for trucks to carry containers to move into or out of the container
yard. It identifies or checks container weigh, number of container, location of
loading container and procedures and help terminal operations safety.
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1.3.1. Terminal layout gates
Figure 1.1: Terminal layout gates
Source: A Case Study. Center for Transportation Research University of Texas (2007)
Each terminal has different gate systems. There are 2 gates in terminal-
entrance gates and exit gates. Entrance gates have duties including checks
procedures, container weight, number and signs of container and truck, location of
loading and unloading container.
Exit gates have same function with entrance gate but it serves only for
outbound truck going from stack area without vehicles insight terminal. Quality of
terminal gate plays an important role for the company development. Terminal gate
is considered as company’s face.
1.3.2. Several model simulations applied in terminal gates
A simulation is developed by Moini (2010) to determine the impact of truck
appointment system implementation at terminal gates thus extending the system’s
application to the truck interchange area (inside the terminal), where trucks proceed
for container pick up and/or drop off. Building upon the work of Boile et al. (2008b)
where a methodology for analyzing dray truck traffic inside the terminal and beyond
the terminal gate on the port access network in an integrated way was presented,
Dougherty (2010) developed a simulation-based approach for modeling different
gates strategies and evaluating the benefits that different operational improvements
may have in reducing congestion in the vicinity of the terminals. Guan & Liu (2009)
used a multi-server queuing model to quantify marine terminal gate congestion for
inbound trucks, evaluate truck waiting cost and explore alternatives for gate system
optimization. Their results indicated truck waiting costs as an issue to be addressed
and for this purpose they proposed a gate appointment system to reduce gate
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joint stock company- Greenport terminal
congestion and increase system efficiency. Huynh (2009) performed an evaluation
study on the scheduling rules of gate appointment systems proposing two types of
scheduling strategies i.e. individual appointment systems (IAS) and block
appointment systems. He concluded that there is a real benefit for a terminal without
an appointment system to employ the IAS as it kept yard cranes highly utilized
while improving the yard turn time. With a focus on the Port of New York/New
Jersey area, Boile et al. (2008a) presented a simulation based modeling approach for
the evaluation of different gate operation strategies and the assessment of the impact
of their implementation on the terminal access network. Extending beyond the
terminal gate, Namboothiri and Erera (2008) used an integer programming- based
heuristic to model and determine the optimal pickup and delivery sequences of daily
drayage operations based on minimal transportation costs and considering the
restrictions imposed by the implementation of a gate appointment system. Huynh
and Walton (2005) developed a simulation model of the Barbours Cut Terminal at
the port of Houston with the objective to reduce truck turn time by examining yard
crane availability and the implementation of a gate appointment system. They
evaluated the maximum number of trucks with appointment for each defined zone
and the time window such that the average truck turn time did not exceed a
maximum. Their results indicated that the implementation of such a system is not
always effective unless its parameters are efficiently determined.
TAS is a best recommendation to relieve container truck congestion in
terminal gates. Boile (2012) mentions that to ease congestion at terminal gates, one
of the proposed recommendations is the implementation of an appointment system
at inbound gates, which can be effective in controlling truck random arrivals,
modifying peak hours of demand, minimizing truck idling, and improving the
utilization of the terminal’s capacity.
1.4. Congestion Overview
1.4.1. Definition of congestion
Normally, congestion is a concept used to describe the speed limit of vehicles
in traffic with the main cause is the large density of vehicles involved. Congestion
usually relates to an excess of vehicles on a portion of roadway at a particular time
resulting in speeds that are slower sometimes much slower than normal or “free
flow” speeds. This phenomenon often occurs in narrow intersections with high
quantities of vehicles participation.
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Table 1.1- Alternate definition of congestion
Definition Author
Traffic congestion occurs when travel
Rosenbloom,1978
demand exceeds the existing road system
capacity.
Congestion is a condition in which the
number of vehicles attempting to use a
roadway at any time exceeds the ability of Rothenberg, 1985
The roadway to carry the load at generally
acceptable service levels.
Congestion is a condition that arises because
The Institute of
more people wish to travel at a given time
Civil Engineers,
than the transportation system can
1989 cited in
accommodate: a simple case of demand
Miller and Li, 1994
Demand exceeding supply.
Capacity When vehicular volume on a transportation
related facility (street or highway) exceeds the Vuchic and Kikuchi,
capacity of that facility, the result is a state of 1994
congestion.
Congestion is the impedance vehicles impose
on each other, due to the speed-flow
relationship, in conditions where the use of a ECMT, 1999
transport system approaches its capacity.
Congestion may be defined as state of traffic
flow on a transportation facility characterized
Bovy and Salomon,
by high densities and low speeds, relative to
2002
some chosen reference state (with low
densities and high speeds).
Congestion is an imbalance between traffic Pisarski, 1990 cited
flow and capacity that causes increased travel in Miller and Li,
time, cost and modification of 1994
Behavior.
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Traffic congestion is travel time or delay in
excess of that normally incurred under light Lomax et al, 1997
or free-flow travel conditions.
Traffic congestion is a condition of traffic
delay (when the flow of traffic is slowed
Weisbrod, Vary and
below reasonable speeds) because the
Treyz, 2001
number of vehicles trying to use the road
exceeds the traffic network capacity to
handle them.
Congestion is the presence of delays along a
physical pathway due to presence of other Kockelman, 2004
Delay- users
travel time Congestion can defined as the situation when
related traffic is moving at speeds below the Downs, 2004
designed capacity of a roadway.
In the transportation realm, congestion
usually relates to an excess of vehicles on a Cambridge
portion of roadway at a particular time Systematic and TTI,
resulting in speeds that are slower-sometimes 2005
much slower-than normal or "free flow"
speeds.
Traffic congestion refers to the incremental
Cost
costs resulting from interference among road VTPI, 2005
related
users.
Definition was more completed and more detailed per year. In “demand
capacity related” factor, definitions had same point which was the high density of
vehicles having low speed relationship over time. Rothenberg (1985) said that
congestion is a condition in which the number of vehicles attempting to use a
roadway at any time exceeds the ability of the roadway to carry the load at generally
acceptable service levels. While Vuchic and Kikuchi (1994) mentioned that when
vehicular volume on a transportation facility (street or highway) exceeds the
capacity of that facility, the result is a state of congestion.
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