Stochastic Analysis of Road Crash Safety in Work Zones Project

This project conducts a stochastic analysis of road crash safety in work zones, focusing on Victoria, Australia. The project begins with an introduction, background research, and a literature review of existing studies on work zone crashes, including driver characteristics, visibility, work zone configuration, and speed. It aims to identify frequent crash causes and analyze crash fatality probability using Monte Carlo simulation with @Risk software. The project also develops correlations between road accidents, the volume of heavy vehicles, highway geometric design parameters, and traffic operating characteristics. The methodology includes data collection from sources like Safe Work Australia and real-life case studies. The project provides recommendations for improving traffic safety, including traffic signs, safety measures, line marking, driver education, and the use of barriers. The findings are presented through data tables, probability graphs, and risk analysis graphs, culminating in conclusions and recommendations for enhancing work zone safety.

CONTENTS
EXECUTIVE SUMMARY I
ACKNOWLEDGEMENT II
STATEMENT OF ORIGINALITY III
CHAPTER 1: INTRODUCTION 1
1.1. OVERVIEW OF THE PREVIOUS STUDY:
1.2. SCOPE OF THE PROJECT:
1.3. AIM OF THE PROJECT:
1.4. OBJECTIVES OF THE PROJECT:
1.5. RESEARCH QUESTIONS:
1.6. RESEARCH METHODOLOGY:
1.7. LIMITATIONS:
1.8. THESIS ORGANIZATION:
CHAPTER 2: CRASH CHARACTERISTICS IN ROAD WORK ZONE
2.1. INTRODUCTION
2.2. WORK ZONE
2.3. CRASHES IN THE WORK ZONE
2.3.1. DRIVER CHARACTERISTICS
2.3.2. VISIBILITY
2.3.3. WORK ZONE CONFIGURATION
2.3.4. SPEED
2.4. SEVERITY OF THE CRASH
2.5. FREQUENCY OF THE CRASHES
CHAPTER 3: LITERATURE REVIEW
CHAPTER 4: STOCHASTIC ANALYSIS FOR ROAD CRASHES IN WORK ZONE
4.1 DEFINING THE PARAMETERS USING PALISADE @RISK
4.2 COMPLYING COLLECTED DATA WITH @RISK
4.3 MONTE CARLO SIMULATION IN PALISADE @RISK
4.4 VALIDATION OF @RISK MODEL

4.5 RESULTS AND CONCLUSION FROM THE @RISK SIMULATION REPORT
CHAPTER 5. DEVELOPMENT OF CORRELATION BETWEEN ROAD
ACCIDENTS,THE VOLUME OF HEAVY VEHICLES,GEOMETRIC
DESIGNPARAMETERS ALONG WITH TRAFFIC OPERATING CONDITIONS
5.1. VOLUME OF HEAVY VEHICLES
5.2. TRAFFIC OPERTING CHARACTERISTICS
5.3. GEOMETRIC DESIGN PARAMETRS
CHAPTER 6. FUTURE WORKS AND RECOMMENDATIONS
IN THE WORK ZONE
CHAPTER 7. CONCLUSION
REFERENCES:

EXECUTIVE SUMMARY
Work zone area and road crashes have been a common topic of research for the past few years. This
research will analyze the road crashes in work zone areas in Victoria, Australia. Work zone areas
are the designated lanes on a road that are allotted only for the work zone related vehicles to be used
in order to load or unload material and transportation of the workers. These lanes are not parking
lanes and regular traffic vehicles are not allowed to use these lanes until the work at the area is
complete. But due to various reasons, regular traffic may end up disrupting the rules and this can
lead to crashes that can range from a small dent in the car to fatal accidents. Reviewing articles
regarding the work zone related road crashes in different countries have been useful for reviewing
the reasons and understanding the different ways through which they can be avoided. They are,
1. Driver Characteristics
Different characteristics of drivers like stress, sleepiness, unsafe lane changes and using of
phones while driving have been identified as reasons for these accidents. The probabilry of this
happening is 0.28.
2. Visibility
When weather conditions are bad or the signage is placed improperly or the lightings during the
night work is not proper crashes can occur and have a probability of 0.33
3. Work Zone Configuration
Unsafe working conditions and improper planning and identification of work zone areas are also
reasons that lead to crashes with a probability of 0.46
4. Speed
While driving, if the speed limit is exceeded or the decisions regarding change of lanes or
braking are miscalculated, the probability of the crashes occurring is 0.40
Correlations between different aspects of road accidents have been developed like the volume of
heavy vehicles, highway geometric design parameters and the traffic operating characteristic.
The heavy vehicles that are mostly used for transportation of goods are trucks and use the
highways frequently. Therefore, they play an important role in the economy of Australia. Out of
the total crashes that are caused on these highways, 80% of them involve trucks and other heavy
vehicles. Traffic operations in the work zone area need to be maintained in order to avoid
accidents. Traffic signs, speed limits and educating the drivers about these signs has been
deemed important.
Different recommendations have been made regarding the improvements of safety in work
zones. They include:
1. Traffic and safety signs
2. Installation of safety measures
3. Line marking
4. Educating drivers and worker
5. Using crash barriers
6. Portable rumble strips

7. Improving infrastructure
8. Well-lit roads
9. Using reverse Cameras
10. Increasing road visibility
Separating the work zone area from the regular roads is possible by using the temporary
barriers. Using them has the potential to reduce the occurrence of crashes. However, sometimes
these barriers itself can be hazardous and lead to crashes. When the barriers are being placed or
removed, the road becomes vulnerable and crashes can occur. Effective and safe use of barriers
is important in order prevent crashes. There are different types of temporary barriers that can be
used for these work zones. They are:
1. Fixed objects
Walls posts, supplies, boulders and other are fixed objects of the work zone.
2. Portable concrete Barriers
Concrete walls that stand between the work zone and the normal roads are portable barriers
3. Ballast filled Barriers
These are plastic shields of polythene are used with ballast and act similar to portable
barriers.
4. Shadow Vehicles
Placing heavy vehicles at the periphery of the work zone will safe guard the workers from
crashes.
5. Vehicle Arresting Systems
Using nets and anchors that absorb energy are essential as vehicle arresting systems

CHAPTER 1
INTRODUCTION
Work zone safety is one of the most crucial topics in the present scenario due to the continuous
increase in the number of accidents caused by the work zones.Studies points towards the different
work zone conditions, safety and work hazards at the work zones due to which there have been
several severe and minor accidents at the work zone. There has been much temporary traffic control
implemented in order to mitigate the safety issues. Nevertheless, the usefulness of these signs has
not been discussed. Numerous researches have been carried out on this topic. Even then, there has
not been any improvement in the situations for a long time.
This project will provide a stochastic analysis for the road crashes at work zone. For this, the
background of the current situations will be discussed along with discussing the literature related to
the road crash safety of the work zone. Extensive research is conducted in order to understand the
cause of the accidents at the work zones, the characteristics of traffic operations will be conferred,
road crash data from safe work Australia and few other international agencies has beenreviewed
concluding the project by giving practical recommendations on work zone safety.
1.1 BACKGROUND RESEARCH
Crashes in the work zone has become a major issue from the past few years as it is causing a greater
number of deaths in the overall work zone fatalities.Australia has a decent safety record towards the
road works, contrasted with the United States which encountered a 50% increase in the fatality rate
at the road work zone.There has been no significant improvement in the situation. Work zones on
highways have been considered to be one of the primary reasons for accidents on the highways.
There has been a significant increase in the work zone related accidents in the past few years. Many
policies have been formulated in order to prevent these crashes and accidents. However, only a few
of them have been practically applied. Even then, their effectiveness has not been discussed
anywhere. (Yang et al.2015)

Fig.1
It is essential to understand the risk factors that lead to these accidents. Not all accidents have the
same reasons. There can be different reasons like the safety norms were not followed by the work
zone staff, or there were not any signs indicating the work being under progress or about the
reduced speed limits. Therefore, it is obligatory to understand the reasons before suggesting the
solutions for the accidents on the highways due to the work zones. (Wei et al.2017)
Safety norms are set in place in order to prevent any small- or large-scale accidents from happening.
If these norms are not followed, the area can be proved to fatal and lead to numerous unaccounted
accidents that could have been easily avoided. (Rhee et al.2016)
1.2. SCOPE OF THE PROJECT
The scope of the project is to discover the causes of road work zone crashes. It also includes
collecting data from different sources like safe work Australia and executing the stochasticanalysis
for the data collected and presenting the results of the analysis using graphs to explain the problems
better and suggesting the better precautionary remedies and methods of reducing the crash
frequency. It also includes reviewing the real-life case studies about the accidents and listing down
the major accident causes. (Gupta, 2018)
The scope also comprises of providing recommendations about the different traffic operation
strategies that can lead to accidents at the work zone area of the highway (Weng et al.2016).
1.3. AIM OF THE PROJECT
The main aim of this project is to conduct a stochastic analysis for road crash at work zone by
listing the causes of the major accidents, review case studies related to the road crashes at work
zone, understanding the operations of traffics and recommending ways to improve the working

conditions around work zone area and collecting information about crashes and analysing it. (Sze
and Song, 2018)
1.4. THE OBJECTIVE OF THE PROJECT
Many objectives need to be fulfilled in order to complete the research on the road crash safety at
work zones (Osman et al.2016)
 To review the frequent causes of crashes at the work zone.
 To analyse crash fatality probability using Monte Carlo simulation with @risk software
 Development of correlation between road accidents, the volume of heavy vehicles,
geometric design parameters of highway along with traffic operating characteristics.
 To propose recommendations and methods for providing safety in the work zone.

CHAPTER 2
CRASHES IN THE WORK ZONE
2.1 INTRODUCTION
This chapter explicates the meaning of a work zone, rules related to the work zone areas, accidents
occurring at the work zone areas in Victoria, Australia along with the causes of these accidents. The
accidents will be further be categorized according to the severity levels like fatal accidents, serious
injury accidents and minor injury accidents. This chapter will also calculate the frequency of
accidents. In order to articulate the solutions for preventing them in the future, the causes of these
accidents will be analysed thoroughly.
2.2 WORK ZONE
Victoria has been continuously working to improve and maintain the state by regularly constructing
new structures, like commercial and non-commercial buildings. While the construction is under
progress, a part of the main highway is specifically dedicated for the transport and construction
vehicles that carry the resources and manpower necessary for the construction. The work zones are
also used for loading unloading construction equipment that will be required at the site. These work
zone areas are approved by the City council of the specific city from the state of Victoria before the
construction work begins. The approval does not allow parking of vehicles in the dedicated work
zone areas. Failure of following the guidelines set by the city council will lead the owner of the
offending vehicle to be fined. (Perry et al.2018)
According to the Manual on Uniform Traffic Control Devices (MUTCD) the work zone area has
divided into four major parts which includes (FHWA 2003).
i) The advance warning area
ii) The transition area
iii) The activity area
iv) The termination area
When the vehicle entering the work zone area, drivers are cautioned about the hazardous upcoming
area in advanced warning area so that they can be careful and are directed into transition area from
the normal or usual road path. The transition area as often as possible structures a bottleneck which
could significantly reduce the traffic. The activity area is the place where the actual road work is

carried out on the road or across the road. In the termination area, the road users are allowed to
return the normal road path and can travel according to normal road rules and conditions.
Component Areas of a Highway Work Zone
Source: ( MUTCD 2003 Edition)

These part or lanes can easily be identified by the signboards put up on the dedicated work zone
lanes and areas that will specify the area and the timings at which these roads will be considered as
a work zone area and the times when they will be considered to be normal roads for regular traffic
to use. An expert for work zone road safety is selected who will look after the maintenance of the
flow of traffic, chart out and explain the traffic safety rules to the workers, and evaluate where the
signboards should be placed. (Weng et al.2016)
2.3 ACCIDENTS AT WORK ZONE AREA
Work zones have been a common sight in Victoria, Australia for the past few years as there has
been an increase in improving and maintaining the highways of the country. However, these work
zone areas can be dangerous to the workers if not fatal. There can be different reasons why these
accidents can be caused. These are not only limited to the construction site itself; these accidents
can also be caused due to regular traffic flow in the areas. (Domenichini et al.2017)
Safety precautions and traffic flow control are always the priority while assigning the work zone
areas for works. The safety inspector responsible for the safety of the workers at the work zone
areas and should be careful enough while inspecting the area for the safety norms. The safety
inspector has to identify the risks that could occur in the specific work area. However, even then
there are times when accidents occur at these work areas. Since these work zone areas are at the

main highways of the state, the workers at the work zone area are bound to come in contact with
high speeding vehicles. Accidents that can be caused at these areas may include: (Weng et al.2015)
The following tables explains the number of fatalities and the major causes of the fatalities in the
work zone from 2007 to 20017.
Source: (Work safe Australia)
Statistics from Work safe Australia between 2007 and 2017.

From the above graph we can see that the majority of the accidents or deaths in the workzone are
caused by the vehicle crashes in and around the work zone area.
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
0
20
40
60
80
100
120
140
160
Fatalities due to vechile collision from 2007 to 2017
Fatalities due to vechile collision from 2007 to 2017
The majority of the accidents in the work zone are caused by the vehicle collision which accounts
for more than 50% of the total fatalities caused each. The crashes in the work zone caused by
vechiles may vary depending upon the situation and place where the crash has taken place. After
analysing the data from the work safe Australia and other government agencies we can say that
there are few major factors that contributing the crsashes in the work zone. The causes of the major
accidents or crashes in the work zone can be listed to:
2.3.1. DRIVER CHARACTERISTICS
1. Unsafe changing of lanes
As the drivers realize late that the lane, they are driving in is allotted for the work zone after a point,
they end up trying to change the lanes in a haste leading to either ramming their vehicle in the
vehicle before them or being hit by the vehicles that follow them.
2. Stress/ Sleeplessness
Driving when sleepy or under a lot of stress can make the drivers careless due to which even after
reading the signboards, they are not able to comprehend them easily. These drivers are at a high risk
of causing accidents or crashing into the work zone area equipment.
3. Using of phone