DRIVER EDUCATION FOR
SAFETY IN ADVERSE DRIVING
CONDITIONS
Final Report 609
Prepared by:
Jack Faucett Associates, Inc.
4550 Montgomery Avenue, Suite # 300N
Bethesda, Maryland 20814
February 2008
Prepared for:
Arizona Department of Transportation
206 South 17th Avenue
Phoenix, Arizona 85007
The contents of the report reflect the views of the authors who are responsible for the
facts and the accuracy of the data presented herein. The contents do not necessarily
reflect the official views or policies of the Arizona Department of Transportation. This
report does not constitute a standard, specification, or regulation. Trade or manufacturers’
names that may appear herein are cited only because they are considered essential to the
objectives of the report. The U. S. Government and The State of Arizona do not endorse
products or manufacturers.
Technical Report Documentation Page
1. Report No.
FHWA- AZ- 08- 609
2. Government Accession No.
3. Recipient’s Catalog No.
5. Report Date
February 2008
4. Title and Subtitle
Driver Education for Safety in Adverse Driving Conditions
6. Performing Organization Code
7. Authors
Jonathan Skolnik
Kristin Noyes
Paul Nguyen
8. Performing Organization Report No.
JACKFAU- 07- 678
10. Work Unit No.
9. Performing Organization Name and Address
Jack Faucett Associates, Inc.
4550 Montgomery Avenue, Suite # 300N
Bethesda, Maryland 20814
11. Contract or Grant No.
SPR- PL- 1-( 69) 609
13. Type of Report & Period Covered
Driver Safety
12. Sponsoring Agency Name and Address
Arizona Department of Transportation
206 S. 17th Avenue
Phoenix, Arizona 85007
Project Manager: John Semmens
14. Sponsoring Agency Code
15. Supplementary Notes
16. Abstract
Under certain adverse driving conditions, often times the driver of a vehicle has inadequate training or education and
ends up taking wrongful action leading to severe crashes. The purpose of this research was to determine the state- of-the-
art practices in educating drivers for safety in certain adverse driving conditions and to develop a realistic module of
a driver education program addressing that topic. In addition, the research sought to determine whether any relevant
laws and regulations related to driving in the State of Arizona need to be changed in order to properly address safety
under adverse driving conditions.
The study consisted of four main tasks, which included a literature review, statistical analysis of Arizona crash data, a
survey of other states regarding their driver education programs, and targeted case studies of selected states and other
private or semi- government agencies involved in driver education curriculum development and implementation.
It is the recommendation of this report that Arizona continue its on- going efforts to convene a driver education task force
consisting of both Arizona Department of Education and Motor Vehicle Department representatives with the goal of
developing uniform standards for both driver education curriculum and training for driver education instructors to apply to
both the public school driver education program and the professional driver training schools.
In addition, because Arizona does not have an existing state- level driver education curriculum, the state should adopt a
complete driver education curriculum as opposed to a module geared towards adverse driving conditions. That said,
should that effort not be possible, it is the recommendation of this report that one of the two adverse conditions related
modules ( Montana or Texas/ Virginia). Both of these modules are well designed and thorough and both would serve
Arizona well. They are similar in their coverage of adverse driving conditions. The choice between the two would come
down to Arizona’s preference between the NIDB model with which the Montana curriculum is more closely aligned, and
the ADTSEA model with which the Virginia/ Texas module is more closely aligned.
17. Key Words
Driver Education Accidents
Safety Fatalities
Adverse Conditions
18. Distribution statement
Document is available to the
U. S. public through the National
Technical Information Service,
Springfield, Virginia, 22161
19. Security Classification
Unclassified
20. Security Classification
Unclassified
21. No. of Pages
169
22. Price
23. Registrant’s Seal
SI* ( MODERN METRIC) CONVERSION FACTORS
APPROXIMATE CONVERSIONS TO SI UNITS APPROXIMATE CONVERSIONS FROM SI UNITS
Symbol When You Know Multiply By To Find Symbol Symbol When You Know Multiply By To Find Symbol
LENGTH LENGTH
in inches 25.4 millimeters mm mm millimeters 0.039 inches in
ft feet 0.305 meters m m meters 3.28 feet ft
yd yards 0.914 meters m m meters 1.09 yards yd
mi miles 1.61 kilometers km km kilometers 0.621 miles mi
AREA AREA
in2 square inches 645.2 square millimeters mm2 mm2 Square millimeters 0.0016 square inches in2
ft2 square feet 0.093 square meters m2 m2 Square meters 10.764 square feet ft2
yd2 square yards 0.836 square meters m2 m2 Square meters 1.195 square yards yd2
ac acres 0.405 hectares ha ha hectares 2.47 acres ac
mi2 square miles 2.59 square kilometers km2 km2 Square kilometers 0.386 square miles mi2
VOLUME VOLUME
fl oz fluid ounces 29.57 milliliters mL mL milliliters 0.034 fluid ounces fl oz
gal gallons 3.785 liters L L liters 0.264 gallons gal
ft3 cubic feet 0.028 cubic meters m3 m3 Cubic meters 35.315 cubic feet ft3
yd3 cubic yards 0.765 cubic meters m3 m3 Cubic meters 1.308 cubic yards yd3
NOTE: Volumes greater than 1000L shall be shown in m3.
MASS MASS
oz ounces 28.35 grams g g grams 0.035 ounces oz
lb pounds 0.454 kilograms kg kg kilograms 2.205 pounds lb
T short tons ( 2000lb) 0.907 megagrams
( or “ metric ton”)
mg
( or “ t”)
mg megagrams
( or “ metric ton”)
1.102 short tons ( 2000lb) T
TEMPERATURE ( exact) TEMPERATURE ( exact)
º F Fahrenheit
temperature
5( F- 32)/ 9
or ( F- 32)/ 1.8
Celsius temperature º C º C Celsius temperature 1.8C + 32 Fahrenheit
temperature
º F
ILLUMINATION ILLUMINATION
fc foot candles 10.76 lux lx lx lux 0.0929 foot- candles fc
fl foot- Lamberts 3.426 candela/ m2 cd/ m2 cd/ m2 candela/ m2 0.2919 foot- Lamberts fl
FORCE AND PRESSURE OR STRESS FORCE AND PRESSURE OR STRESS
lbf poundforce 4.45 newtons N N newtons 0.225 poundforce lbf
lbf/ in2 poundforce per
square inch
6.89 kilopascals kPa kPa kilopascals 0.145 poundforce per
square inch
lbf/ in2
SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380
TABLE OF CONTENTS
EXECUTIVE SUMMARY................................................................................................ 1
CHAPTER 1: INTRODUCTION ....................................................................................... 7
CHAPTER 2: LITERATURE REVIEW ............................................................................. 9
2.1: DEFINITION OF “ ADVERSE DRIVING CONDITIONS” ...................................... 9
2.2: EXAMPLE CURRICULUM ADDRESSING ADVERSE DRIVING ...................... 13
2.3: SUMMARY OF RESEARCH ON ISSUES RELATED TO ADVERSE DRIVING
CONDITIONS AND DRIVER EDUCATION…………………………………….…. 19
CHAPTER 3: STATISTICAL ANALYSIS OF ARIZONA ACCIDENT DATA ................. 29
3.1: ARIZONA CRASH DATA................................................................................... 29
3.2: METHODOLOGY.............................................................................................. 32
3.3 ACCIDENTS AND FATALITIES INVOLVING ADVERSE DRIVING................. 36
3.4 ACCIDENTS AND FATALITIES INVOLVING ADVERSE DRIVING AND
DRIVER EDUCATION........................................................................................ 42
3.5 CONCLUSIONS AND RECOMMENDATIONS................................................... 47
CHAPTER 4: SURVEY OF STATE DRIVER EDUCATION OFFICIALS ........................ 49
4. 1 SURVEY METHODOLOGY ............................................................................... 49
4.2 SURVEY RESULTS............................................................................................ 50
4.3 SUMMARY OF FINDINGS................................................................................. 73
CHAPTER 5: RESULTS OF CASE STUDIES OF “ BEST PRACTICE” STATES............. 75
5.1 OREGON DEPARTMENT OF TRANSPORTATION ( ODOT).............................. 76
5.2 DELAWARE DEPARTMENT OF EDUCATION ................................................. 83
5.3 IDAHO STATE DEPARTMENT OF EDUCATION.............................................. 86
5.4 MONTANA OFFICE OF PUBLIC INSTRUCTION .............................................. 90
5.5 MICHIGAN DEPARTMENT OF STATE…………………………………………… 95
5.6 ARIZONA DEPARTMENT OF TRANSPORTATION........................................... 98
5.7 TEXAS EDUCATION AGENCY, DRIVER TRAINING DIVISION.................... 100
CHAPTER 6: CASE STUDY OF OTHER ORGANIZATIONS ...................................... 107
6.1 LIST OF AGENCIES INTERVIEWED AND TOPICS COVERED ...................... 107
6.2 RESULTS OF AGENCY INTERVIEWS............................................................. 108
CHAPTER 7: CONCLUSIONS AND RECOMMENDATIONS ..................................... 125
7.1 A REVIEW OF WHAT THE TEAM HAS LEARNED......................................... 125
7.2 CURRICULUM/ MODULE RECOMMENDATIONS .......................................... 127
7.3 OTHER LEGAL OR REGULATORY ACTIONS RELATED TO DRIVING IN
ARIZONA......................................................................................................... 139
7.4 SUMMARY OF RECOMMENDATIONS AND REQUIRED RESOURCES ........ 141
BIBLIOGRAPHY .................................................................................................................. 145
APPENDIX A: ARIZONA TRAFFIC ACCIDENT REPORT.......................................... 149
APPENDIX B: STATE ADMINISTRATORS OF DRIVER EDUCATION...................... 153
APPENDIX C: DRIVER EDUCATION SURVEY.......................................................... 157
LIST OF EXHIBITS
Exhibit 1- 1. Module Recommendations………………………………………………..... 4
Exhibit 3- 1. Summary Table from the 2005 Arizona Crash Facts ................................... 30
Exhibit 3- 2. Adverse Condition Data Fields..................................................................... 33
Exhibit 3- 3. Driver Education Data Fields ....................................................................... 35
Exhibit 3- 4. U. S. Vehicular Deaths per 100,000 People by Age, 2002............................ 35
Exhibit 3- 5. Number and Percent of Incidents by Type of Adverse Condition
( 2001- 2005)................................................................................................. 37
Exhibit 3- 6. Number of Incidents ( 2001- 2005) ................................................................ 39
Exhibit 3- 7. Percent of Incidents with Adverse Conditions ............................................. 39
Exhibit 3- 8. Number and Percent of Fatalities by Type of Adverse Condition
( 201- 2005)................................................................................................... 40
Exhibit 3- 9. Number of Fatalities ( 2001- 2005) ................................................................ 42
Exhibit 3- 10. Percent of Fatalities with Adverse Conditions ............................................ 42
Exhibit 3- 11. Number and Percent of Incidents by Type of Adverse Condition and
Driver Education Indicator ( 2005)............................................................. 44
Exhibit 3- 12. Percent of Incidents with Adverse Conditions and Driver Education
Indicators................................................................................................... 45
Exhibit 3- 13. Number and Percent of Fatalities by Type of Adverse Condition and
Driver Education Indicator ( 2005)............................................................ 46
Exhibit 3- 14. Percent of Fatalities with Adverse Conditions and Driver Education
Indicators................................................................................................... 47
Exhibit 3- 15. Arizona and US Comparison Table from the 2005 Arizona Crash
Facts .......................................................................................................... 48
Exhibit 4- 1. Agencies Responsible for Curriculum Development & Implementation..... 51
Exhibit 4- 2. Q- 3: Through What Means is Driver Education Implemented?.................. 54
Exhibit 4- 3. Q- 4: What Elements Comprise Your Driver Education Program?.............. 55
Exhibit 4- 3A. Q- 4A: In- Class Curriculum ( Number of Hours)....................................... 56
Exhibit 4- 3B. Q- 4B: Driving Simulator Curriculum ( Number of Hours) ....................... 56
Exhibit 4- 3C. Q- 4C: Behind- The- Wheel ( BTW) Curriculum ( Number of Hours) ......... 57
Exhibit 4- 4. Q- 5: What Delivery Methods Are Used For Driver Education? ................. 58
Exhibit 4- 5. Q- 6: Is Additional Driver Education Required After Initial Receipt of
License? ............................................................................................. 59
Exhibit 4- 6. Q- 7: Are All Elements of Driver Education Implemented Con-currently?
.......................................................................................... 61
Exhibit 4- 7. Q- 9: Does Your Curriculum Address Adverse Driving Conditions? .......... 62
Exhibit 4- 7A. Summary of Adverse Driving Conditions Definitions and Training
Program.................................................................................................... 63
Exhibit 4- 8. Q- 10: Is Effectiveness of Driver Education Program Measured? ............... 66
Exhibit 4- 9. Summary of Driver Education Program Evaluation Efforts......................... 67
Exhibit 4- 10. Q- 11: What Is Your Perception of the Effectiveness of Driver
Education in Your State.......................................................................... 68
Exhibit 4- 11. Q- 12: Are There Components of Your Driver Education Program
That are More Effective? ............................................................................ 69
Exhibit 4- 12. Q- 13: Does Your Driver Education Program Cover All Subjects It
Should? .................................................................................................... 70
Exhibit 4- 13. Q- 14: Does Your Driver Education Program Utilize Delivery Methods
It Should? ................................................................................................. 71
Exhibit 4- 14. Q- 15: Are There Planned Changes Or Improvements To Your Driver
Education Program That Have Not Yet Been Implemented?.................. 72
Exhibit 5- 1. Example of Academic Requirements for GDL Program Entrance……….. 85
Exhibit 5- 2. Idaho Department of Education Driver Education Curriculum Standards.. 87
Exhibit 7- 1. Summary of Recommendations…………………………………………. 141
GLOSSARY OF ACRONYMS
AAA American Automobile Association
AAMVA American Association of Motor Vehicle Administrators
ABS Anti- locking Brake System
ADE Arizona Department of Education
ADTSEA American Driver and Traffic Safety Education Association
AzDOT Arizona Department of Transportation
BTW Behind the Wheel
CD- ROM Compact Disc Read- Only Memory
DDSEA Delaware Driver Safety Education Association
DE Driver Education
DEPIA Driver Education Provider and Instructor Act of October 2006
DETA Driver Education and Training Administers
DMV Department of Motor Vehicles
DOE Department of Education
DOT Department of Transportation
DSAO Diocesan Social Action Offices
DSFL Driving Skills for Life
DVD Digital Video Disc
FHWA Federal Highway Administration
FMCSA Federal Motor Carrier Safety Administration
FTE Full- Time Equivalent
GDL Graduated Licensing Program
GHSA Governor’s Highway Safety Association
HB House Bill
JFA Jack Faucett Associates
MMUCC Model Minimum Uniform Crash Criteria Guidelines
MTV Music Television
MVD Motor Vehicle Division
NDTI National Driver Training Institute
NHTSA National Highway Traffic Safety Association
NIDB National Institute for Driver Behavior
LOS- POT Line- of- Sight and/ or Path- of- Travel
OAR Oregon Administrative Rules
ODE Oregon Department of Education
ODOT Oregon Department of Transportation
OPI Office of Public Instruction
OTESA Oregon Traffic Safety Education Association
OTSC Oregon Transportation Safety Committee
PDE Pennsylvania Department of Education
PTDE Parent Taught Driver Education
RMV Registry of Motor Vehicles
SDE State Department of Education
TAC Technical Advisory Committee
TEA Texas Education Agency
TRB Transportation Research Board
TSD Transportation Safety Division
TTI Texas Transportation Institute
WOU Western Oregon University
ZED Zero Error Driving
1
EXECUTIVE SUMMARY
Introduction
Under certain adverse driving conditions, often times the driver of a vehicle has inadequate
training or education and ends up taking wrongful actions leading to severe crashes and injuries.
Examples of such situations include a tire blowout in the middle of a high speed facility, driving
during a dust storm, driving too closely behind a large truck, approaching a sudden bottleneck or
emergency vehicle in the roadway, etc. Not knowing how to avoid an impending collision, many
drivers do not take the right emergency action in such situations. Moreover, any inappropriate
action by a single driver on a roadway facility can result in crashes of various severities
involving one or more vehicles and other road users.
Poor driver behaviors that lead to crashes and injuries cannot be prevented by highway design or
traffic control devices. This study sought to identify those driver behaviors that lead to crashes
and that could be added to Arizona’s driver education program to train the reasonable driver on
how to avoid such crashes.
Purpose of This Study
The purpose of this research was to determine the state- of- the- art practices in educating drivers
for safety in certain adverse driving conditions and to develop a realistic module of a driver
education program addressing that topic. In addition, the research sought to determine whether
any relevant laws and regulations related to driving in the State of Arizona should be changed in
order to properly address safety under adverse driving conditions.
How This Study Was Conducted
The study consisted of four main tasks, which included a literature review, statistical analysis of
Arizona crash data, a survey of other states regarding their driver education programs, and
targeted case studies of selected states and other private or semi- government agencies involved
in driver education curriculum development and implementation.
Literature Review
The literature review compiled and summarized the current body of technical reports,
educational materials, papers and articles pertaining to adverse driving conditions and the
impacts of driver education on adverse driving conditions- related crashes. The purpose of the
literature review was three- fold:
1) To amalgamate the leading definitions of the term “ adverse driving conditions” and
create an operational definition to be applied in the quantitative analysis of Arizona crash
data;
2) To collect examples of model curriculum addressing driver education for adverse driving
conditions; and
2
3) To summarize the knowledge gained through a literature search on crash cause statistics,
the impacts of driver education on crashes and adverse driving conditions- related crashes
in particular, and policy issues related to highway safety in general.
Analysis of Arizona Crash Data
The statistical analysis of Arizona crash data was conducted to extract whatever information may
be available relative to crashes under adverse driving conditions. This data was analyzed to
ascertain whether any sort of driver training might have reduced the frequency or severity of
these crashes.
State Survey and Case Study
The survey of officials from other states was conducted to ascertain information on each state’s
existing driver education program and the estimated effectiveness of those programs.
Information was also solicited on desired or planned improvements that may not yet have been
made. More detailed information on driver education for safety in adverse conditions was also
collected.
Points of contact were obtained for all 50 states. A cover letter and link to the online survey were
then e- mailed to each state contact. Survey responses were received electronically via online
response over a period of 5 weeks with additional responses obtained as a result of follow- up
phone calls.
The second part of this task involved conducting more detailed follow- up case studies of six
states, in addition to a more detailed analysis of Arizona’s program. These case studies examined
the following attributes of the programs in the selected states:
Mission and rationale,
Program description,
Implementation and participation,
Training materials and methods,
Effectiveness and related factors.
States were selected based on geographical factors, innovative approaches, measured or
anecdotal success in improving traffic safety and availability of well- formulated curriculum or
training module materials. States interviewed in addition to Arizona included: Montana, Texas,
Michigan, Oregon, Delaware and Idaho.
Other Entity Case Study
Private or semi- government agencies were interviewed to ascertain what driver education
programs currently exist and to gather their opinions and willingness to sponsor an improved
driver education program that includes an added element for driving in adverse conditions.
3
The entities interviewed were selected based on information gained through the literature review
and other subsequent research into the primary entities engaged in either the research or
development of driver education curricula. They included:
Governor’s Highway Safety Association ( GHSA),
National Institute for Driver Behavior ( NIDB),
National Highway Traffic Safety Administration ( NHTSA),
American Driver and Traffic Safety Education Association ( ADTSEA),
AAA ( American Automobile Association) Foundation for Traffic Safety.
Study Findings
The literature review revealed that based on existing, albeit limited research, driver education is
not terribly effective in reducing crashes by novice drivers. However, it was also a point in the
literature that evaluating the effectiveness of driver education is difficult in that driver education
has traditionally not been tasked with teaching or specifically influencing traffic safety. Rather, it
has taken on the role of teaching driving skills. Consequently, crash rates are not necessarily a
reasonable measure of the traditional driver education program’s performance or effectiveness.
Moreover, the literature revealed that there appear to be many educational tools, driver safety
behaviors and other identifiable factors that could be incorporated into driver education in order
to make it more responsive to the outcome of reducing crashes should we, as a society, decide
that should be an intended purpose of driver education.
In looking at Arizona vehicle crash statistics between 2001 and 2005, it was found that adverse
conditions are present in just fewer than 40 percent of accidents and approximately 60 percent of
fatalities. When cross- tabulated with identified driver education indicators, this strong correlation
is maintained. The results indicate that both adverse conditions and driver education indicators
are present in about a third of accidents and half of fatalities.
The survey and case study exercises revealed there is a great disparity amongst states in terms of
how driver education is addressed and the specific topics that are covered under driver education
programs. In addition, there is a groundswell of individuals particularly active in the area of
driver education that is working hard to change that fact. Not only do many proponents of driver
education reform seek some uniformity amongst driver education programs, or at least the
standards on which they are based, but many also seek to promote the basic premise that driver
education needs to address certain key driver behaviors that should be taught and reinforced
through proper training and education in order to minimize the risky behaviors that lead to
crashes.
There exist high quality and fully applicable driver education curricula as well as stand alone
driver education modules addressing driving under adverse conditions that Arizona could adopt
to enhance the state’s driver education program. There is no compelling reason to develop a
completely new curriculum or module.
There are two primary national level sources of driver education curriculum and/ or standards
including the Driver Education and In- Car Curriculum developed by ADTSEA and the Driving
4
Behaviors for Risk Prevention developed by Fred Mottola of NIDB. Moreover, a number of
states have recently developed driver education curricula, some of which specifically address the
topic of safety under adverse driving conditions. Some of these curricula align themselves
directly with either the NIDB risk prevention model or the ADTSEA model, others have adopted
some aspects of these models, while still others have been developed independently.
The research identified four of the best examples of these modules and curricula. The
recommendation on which to use is dependent on several factors that only the Arizona
Department of Transportation ( AzDOT) can determine including:
the level of effort the state wishes to expend on the issue of improving driver education,
the legal or regulatory actions the state is interested in pursuing, and
the nature of the reform the state is interested in addressing, i. e. comprehensive program
changes, limited program changes including adoption of full driver education curriculum,
limited program changes including adoption of one module of a driver education
curriculum addressing adverse conditions.
The recommendations and the rationale for adopting each option are summarized in the table
below.
Exhibit 1- 1: Module Recommendations
Curriculum/ Module
Recommendations
Circumstances Under
Which to Implement
Required Resources
1) Oregon Driver
Risk Prevention
Curriculum
Desire to implement a full
and complete national level
driver education curriculum
based on NIDB driver risk
prevention model that is
readily available, but which
will require some
consultation with developer.
Full CD- ROM containing all
curriculum materials, student activities,
quizzes, etc. provided with this report
and available on line. Oregon DOT
estimates 100 hours necessary to train
instructors who will use curriculum.
Developer of curriculum, however,
must grant permission for use of
materials. Conversations indicate that
permission would be granted only with
some fee- based consultation ( minimum
hourly fee is $ 125) on his part
regarding use, understanding and
implement of the materials.
5
Curriculum/ Module
Recommendations
Circumstances Under
Which to Implement
Required Resources
2) ADTSEA
Curriculum
Desire to implement a full
and complete driver
education curriculum based
on national standard which is
readily available at a fixed
price and limited consultation
with developer.
CD- ROM can be ordered online
including all curriculum discs,
recommended videos, printed
materials, and parent mentor guide for
$ 225 ( ADTSEA members $ 175) plus
$ 25 shipping and handling.
Limited consultation ( no fee) would be
required in order to obtain usage rights
and to discuss distribution and
attribution.
3) Montana Driver
Education and
Training Curriculum
Guide
---------
3a) Montana Module
14, Strategies for
Adverse Conditions
Desire to implement full and
complete driver education
curriculum incorporating
some NIDB driver risk
prevention concepts, but
organized in more traditional
fashion and including a
module on adverse
conditions.
--------
Desire to adopt a stand- alone
module on adverse conditions
that incorporates many driver
risk prevention concepts and
covers adverse conditions
topics including: glare, low
light, darkness, fog, smoke,
dust, rain, winter weather and
reduced traction.
All materials available for download
free of charge.
Developer willing to provide fee based
consultation for training, curriculum
modification or other purposes.
4) Texas/ Virginia,
Module 8, Driver
Responsibilities:
Adverse Conditions
Desire to adopt stand- alone
module on adverse
conditions that includes the
adverse conditions topics of:
visibility, extreme weather,
vehicle restraints, roadway
and vehicle technologies,
traction loss and that
incorporates some driver risk
prevention concepts and is
part of a curriculum that
largely follows the ADTSEA
curriculum model.
All materials available for download
online free of charge.
6
Recommendations
It is the recommendation of this report that Arizona continue its on- going efforts to convene a
driver education task force consisting of both Arizona Department of Education and Motor
Vehicle Division representatives with the goal of developing uniform standards for both driver
education curriculum and training for driver education instructors to apply to both the public
school driver education program and the professional driver training schools.
In addition, because Arizona does not have an existing state- level driver education curriculum,
the state should adopt a complete driver education curriculum as opposed to a module geared
towards adverse driving conditions. That said, should that effort not be possible, it is the
recommendation of this report that a training module very similar to one of the two adverse
conditions related modules ( Montana or Texas/ Virginia) presented in the table above be
implemented. Arizona may need to tailor its modules to take care of the local or regional
conditions. Both of these modules are well designed and thorough and both would serve Arizona
well. They are similar in their coverage of adverse driving conditions. The choice between the
two would come down to Arizona’s preference between the NIDB model with which the
Montana curriculum is more closely aligned, and the ADTSEA model with which the
Virginia/ Texas module is more closely aligned.
7
CHAPTER 1: INTRODUCTION
Under certain adverse driving conditions, often times the driver of a vehicle has inadequate
training or education and ends up taking inappropriate action leading to severe crashes.
Examples of such situations include a tire blow- out in the middle of a high speed facility, driving
during a dust storm, driving too closely behind a large truck, approaching a sudden bottleneck or
emergency vehicle in the roadway, etc. Not knowing how to avoid an impending collision, many
drivers do not take the right emergency action in such situations. Moreover, any erroneous action
by a single driver on a roadway facility can result in crashes of various severities involving one
or more vehicles and other road users.
Poor driving behaviors cannot be prevented by highway design or traffic control devices. This
study sought to identify those driver behaviors that lead to crashes and that need to be added to
Arizona’s driver education program to train the reasonable driver on how to avoid such crashes.
The purpose of this research was to determine the state- of- the- art practices in educating drivers
for safety in certain adverse driving conditions and to find a realistic module of a driver
education program addressing that topic. In addition, the research sought to determine whether
any relevant laws and regulations related to driving in the State of Arizona need to be changed in
order to properly address safety under adverse driving conditions.
This was accomplished through the conduct of four primary tasks including a literature review,
statistical analysis of Arizona crash data, a survey of other states regarding their driver education
programs, and targeted case studies of selected states and other private or semi- government
agencies involved in driver education curriculum development and implementation.
Consequently, the remainder of this report is organized into the following chapters:
Chapter 2: Literature Review - compiles and summarizes the current body of technical
reports, educational materials, papers and articles pertaining to adverse driving conditions
and the impacts of driver education on adverse driving conditions- related crashes and
establishes a working definition of “ adverse driving conditions.”
Chapter 3: Statistical Analysis of Arizona Accident Data - provides the results of a
statistical study of Arizona crash data including information relative to crashes under
adverse driving conditions; and analysis to ascertain whether driver training might have
reduced the frequency or severity of these crashes.
Chapter 4: Survey of State Officials – presents results of survey conducted to ascertain
information on each state’s existing driver education program and the estimated
effectiveness of those programs.
Chapter 5: Case Studies of Best Practice States – documents case studies of six states
with exemplary driver education programs and/ or driver education curriculum in addition
to a more detailed analysis of Arizona’s driver education program.
Chapter 6: Case Studies of Private or Semi- Government Agencies – documents case
studies of five entities actively engaged in the development and/ or implementation of
driver education curriculum.
Chapter 7: Conclusions and Recommendations – provides recommendations on the
implementation of a realistic driver education curriculum and/ or module to address the
8
state’s desire to focus on improving safety under adverse driving conditions and
addresses other actions that could be taken by the state of Arizona in terms of
implementing certain laws or regulations related to driving in the state.
The conduct of this study was guided by a Technical Advisory Committee ( TAC). The
responsibilities of the TAC included:
Provide guidance to the project by making timely responses to any relevant questions
posed by the project researcher.
Assist in obtaining access to any official data, records, or information needed for
research.
Review progress reports in a timely manner to provide feedback and ensure that the
project stays on course.
Review and approve ( if satisfactory) the final report.
Provide reasonable assistance in the oral presentation to the Research Council or other
designated audience.
Make the best effort to implement recommendations that would be beneficial to the
Department or other government agencies and/ or the traveling public.
As part of this process, TAC members have provided comments on this report. Where possible
those comments have been used to guide revisions to the report. In some instances, especially
where the changes requested in the comments could not be incorporated or otherwise
accommodated, a footnote was added to discuss the comment.
9
CHAPTER 2: LITERATURE REVIEW
This chapter presents the findings of a literature review designed to compile and summarize the
current body of technical reports, educational materials, papers and articles pertaining to adverse
driving conditions and the impacts of driver education on adverse driving conditions- related
crashes. The purpose of this literature review is three- fold:
1) To amalgamate the leading definitions of the term “ adverse driving conditions” and
create an operational definition that can be applied in the quantitative analysis of Arizona
Crash Data;
2) To collect examples of model curriculum addressing driver education for adverse driving
conditions; and
3) To summarize the knowledge gained through the literature search in the areas of crash
cause statistics, the impacts of driver education on crashes and adverse- driving-conditions-
related crashes in particular, and policy issues related to highway safety in
general.
Consequently, this chapter is organized into the following three sections:
Section 1 summarizes the common definitions of adverse driving conditions used by the
Federal government, State Departments of Transportation ( DOTs), Departments of Motor
Vehicles ( DMVs), and other driver safety organizations and training modules, and
presents a suggested working definition for purposes of this project.
Section 2 presents a list of model curricula addressing driver education for adverse
driving conditions and provides a preliminary review of the applicability to this project of
each item on that list.
Section 3 provides a discussion of various issues related to driver education for adverse
driving conditions including policy issues, crash statistics and the results of research in
the area of driver education impacts on driver behavior and crashes.
2.1: Definition of “ Adverse Driving Conditions”
A review of all available literature found that the term “ adverse driving conditions” is a phrase
often used, but never thoroughly or consistently defined. The meaning of adverse driving
conditions is most commonly associated with poor weather conditions or poor visibility. In fact,
several drivers’ training manuals often use the term interchangeably with the term “ adverse
weather conditions.”
The excerpt below from Hours of Service regulations established by the Federal Motor Carrier
Safety Administration provides an example of the commonly used weather- based definition.
“ Adverse driving conditions mean snow, sleet, fog, other adverse weather
conditions, a highway covered with snow or ice, or unusual road and traffic
conditions, none of which were apparent on the basis of information known to the
person dispatching the run at the time it was begun.” 1
1 Federal Motor Carrier Safety Administration, Hours of Service Regulations, 49 CFR, § 395.2 Definitions
10
However, the literature review revealed that adverse driving conditions are not strictly limited to
weather and its impact on road conditions. Adverse driving conditions may include any number
of unfavorable and unexpected driving circumstances that affect the driver’s ability to see and
control the vehicle such as poor lighting conditions, road/ construction debris, road congestion or
other traffic conditions, road construction or other road surface issues, and vehicle malfunction.
An example of this type of expanded definition comes from the NHTSA, which defines adverse
driving conditions through a set of five conditions including:
Slippery roads: mud, rain, ice, snow, wet leaves, hailstones, sleet, sand or gravel
Limited visibility: fog, smoke, dust, snow, rain, sunlight, dawn and dusk
Vehicle control problems: wind
Extreme temperatures: heat and cold
Catastrophic weather conditions, e. g. situations that occur occasionally without much
warning; flooding and flash floods, lightning, tornado, earthquake2
An example of a State Department of Transportation definition of “ adverse conditions” which is
currently used by both the State of Texas3 and the State of Virginia4 is:
Visibility in Adverse Conditions – e. g. glare, darkness ( night- time driving), weather-related
visibility issues such as rain, fog, smoke, snow
Extreme Weather Conditions – e. g. flash- flooding and low water crossings, extreme
temperatures, strong winds,
Protecting Occupants – e. g. seat belt use, airbag protection, proper steering wheel and
headrest adjustment, proper hand position
Roadway and Vehicle Technology – e. g. intersections, guard rails, crash attenuators,
rumble strips, traffic calming devices, shoulders, medians, message signs, turn bay lanes,
anti- lock brakes, traction control devices, suspension control devices, electronic
stability/ active handling systems, crumple zones, door latches, glass, headlights.
Traction Loss Concerns – e. g. uneven road surfaces, wet leaves, rain or standing water,
ice and snow, mud, sand/ gravel, negative- banked curves.
Operational Definition Adverse Driving Conditions
Through review of the definitions of adverse conditions found in the literature, consideration of
the discussion of adverse conditions in the project Statement of Work, and the data available
2 “ Driving Under Adverse Weather Conditions” School Bus Driver In- Service Safety Series, NHSTA.
http:// www. nhtsa. gov/ people/ injury/ buses/ UpdatedWeb/ index. html. Note: This definition comes from a school bus
driver education manual. The “ vehicle control problems” and “ extreme temperature” conditions relate more to
school bus operations than to regular vehicle situations.
3 “ Texas Driver Education Classroom and In- Car Instruction Model Curriculum, Module Eight: Texas Driver
Responsibilities: Adverse Conditions.” Texas Education Agency, Texas Department of Public Safety, Texas
Department of Transportation.
4 “ Curriculum Scope and Sequence Modules for Driver Education in Virginia, Module Eight Driver
Responsibilities: Adverse Conditions.” Virginia Department of Education and Virginia Department of Motor
Vehicles, August 2001
11
from the Arizona State Crash Forms, the following operational definition of adverse driving
conditions is suggested:
" Environmental and other factors affecting visibility and traction including: 1) darkness, 2)
weather conditions ( e. g. fog, rain, snow, flood, smoke, severe wind, extreme temperatures,
etc.), 3) road conditions and construction, and 4) vehicle stability and traction control ( e. g.
tire pressure and wear, and brake issues)."
This definition includes driver error, vehicle maintenance and road conditions only as they relate
to visibility, vehicle stability and/ or traction control. More specifically, this includes the
following driver actions and circumstances and/ or driver reactions to those circumstances:
Breaking or accelerating too hard/ fast;
Over- steering;
Worn or improperly inflated tires;
Improper steering with Anti- locking Brake Systems ( ABSs) and other differences in
performance between vehicles equipped with ABSs versus non- ABSs;
Misadjusted brakes;
Defective headlights or taillights;
Defective windshield wipers;
Defective steering; and
Construction or road conditions involving uneven road surfaces, sand or gravel,
obstructions, defective shoulders, negatively banked curve, temporary lane changes.
Though not defining the term specifically, the Statement of Work for this project indicates a
preference that the definition be inclusive of certain driver behaviors and vehicle maintenance
issues beyond those associated solely with weather and lighting conditions. The proposed
operational definition, therefore does not follow the strictly weather- related definitions
occasionally found in the literature, but rather extends into many of the other areas found in the
literature to be considered “ adverse conditions.” Moreover, the proposed operational definition
recognizes the inherent overlap between the concepts of driving under adverse conditions and
driver error and is consequently, inclusive of certain driver errors.
In its report Remedies for Driver Error, 5 Jack Faucett Associates include a taxonomy of driver
errors attributed to Wierwille et al., 2002. That taxonomy illustrates this overlap in its inclusion
of “ infrastructure, environment problems” including traffic control device related, roadway
related ( alignment, sight distance and delineation) and weather/ visibility related problems. The
proposed operational definition stops short of including many other driver errors because we
believe focusing only on those areas of driver error involving circumstances largely out of the
control of the driver is compatible with the definitions of adverse conditions found in the
literature.
To allow for the type of statistical analysis required in this project, the definition of adverse
driving conditions needed to be operationalized vis- à- vis the available data. That data comes
5 Hutabarat, R., J. Lam, and M. Lawrence. Remedies for Driver Error. FHWA AZ 04 567. Arizona Department of
Transportation, August 2004.
12
from the Arizona State Crash Forms Page 3 diagram ( See Appendix A). Following that diagram
and the definition discussed above, the following fields of information were utilized in
performing the statistical analysis for this project: 6
16 Light Condition
16.2 Dawn or dusk
16.3 Darkness
17 Weather Condition
17.2 Cloudy
17.3 Sleet/ hail
17.4 Rain
17.5 Snow
17.6 Severe Crosswinds
17.7 Blowing Sand, Soil, Dirt, Snow
17.8 Fog, Smog, Smoke
22 Unusual Road Condition
22.1 Under Construction, Traffic Allowed
22.2 Under Construction, No Traffic Allowed
22.3 Under Repairs
22.4 Holes, Ruts, Bumps
22.5 Obstruction, Protected
22.6 Obstruction, Unprotected
22.7 Obstruction, Unlighted at Night
22.8 Defective Shoulders
22.9 Changing Road Width
22.10 Water ( Standing or Moving)
22.11 Temporary Lane Closure
26 Road Surface Condition
26.2 Wet
26.3 Sand, Mud, Dirt, Oil, Gravel
26.4 Snow
26.5 Slush
26.6 Ice
26.7 Other
26.8 Unknown
6 This list was reviewed and approved by the TAC. After the statistical analysis was complete, several additional
comments on the list were received from TAC members that, while valid, were not timely enough to be included in
the analysis. For example, it was mentioned by a TAC member that perhaps more vehicle maintenance conditions
could have been included, although no specific data were identified. Another TAC member suggested the definition
should include wind, trailer sway crashes, and shoulder drop off. Note that severe crosswinds are already included
in the analysis and accounted for a total of 80 crashes in 2005. There are also statistics included on defective
shoulders, which accounted for 41 total crashes. There was also a comment on micro level data, including
overcorrecting, skidding or other maneuvers that could have been prevented through driver training although there
was no data on the crash forms to qualify these measures.
13
28 Violations/ Behavior
28.2 Speed Too Fast for Conditions
28.10 Knowingly Operated With Faulty or Missing Equipment
29 Vehicle Conditions
29.2 Defective Brakes
29.3 Defective Steering
29.4 Defective Headlights
29.5 Defective Tail Lights
29.7 Puncture or Blowout
29.8 One or More Smooth Tire
29.10 Defective Windshield Wipe
2.2: Example Curriculum Addressing Adverse Driving
This section presents a review of nine documents that could serve as models for the module ( or
modules) of a driver education element focused on driving in adverse conditions that will be
developed under this project. Each document is discussed in terms of the definition of adverse
conditions utilized in the module and an assessment of the degree to which the document is
applicable to development of the module for this project.
1) Lonero, L., Clinton, K., Brock, J., Wilde, G., Laurie, I. Black, D. “ Novice Driver
Education Model Curriculum Outline.” AAA Foundation for Traffic Safety. 1995.
The AAA Foundation for Traffic Safety sponsored a project to “ reinvent” driver education
into a form that reduces crashes by novice drivers. This paper identifies way to restructure
driver education to realize its potential for improving safety. It includes discussion of the
needs of novice drivers; novice driver skills and abilities; novice drivers’ choices and
behavior; hazard perception, risk evaluation and risk acceptance; parent/ guardians and novice
drivers; integrating complementary skills and values; developing supporting influences for
novice drivers; graduated licensing and driver education links; and strategic directions for
driver education.
Recommendations include:
Develop software for teaching and testing knowledge and skills in an individual, self-paced,
automated way.
Develop interactive multi- media units for training and testing driver attention and
visual detection as well as risk perception and evaluation.
Develop software based on game- theory models to diagnose, clarify, and reinforce
modification of new drivers' risk- taking styles and to demonstrate their consequences.
Develop improved in- car instruction and instrumentation to teach driving and
perception skills and provide feedback on driver performance.
Develop participative classroom units for peer- focused seminars, individual study
projects, and group work. These are needed to clarify health and safety values and to
enhance personal motivation and social responsibility.
14
Develop instructor training to support the use of new interactive media, participative
classroom units, and in- car perception units. The need is to reinvent the teacher and
instructor's role, enriching the job by shifting the emphasis from information provider
to that of coach or mentor for health and safety motivation, social values, and life
skills.
Develop tools, models, and instruction units that support parent involvement in young
driver education.
Develop models and incentives that mobilize community, industry, and government
support for coordinating positive influences on novice drivers. These should include
links between the driver education and health promotion communities and between
driver education and insurance providers.
Coordinate development of graduated licensing systems with driver education. Move
to multi- stage education in the graduated licensing jurisdictions. These driver
education formats should also be pilot tested for effectiveness and market acceptance
in non- graduated jurisdictions.
Expand the integration of driver education topics into other school subjects,
particularly health, community service, and other values- related activities.
Though this paper is not specifically directed toward driving in “ adverse conditions”, many
of the identified behaviors and risk factors for novice drivers are related to adverse driving
conditions. Section 4 of the paper addresses instructional methods and activities and relates
them to performance objectives.
2) “ Montana Driver’s Manual for Obtaining a License to Drive, Chapter 6 Adverse Driving
Conditions and Driver Emergencies.” Montana Office of Public Instruction, Division of
Health Enhancement and Safety, Montana Department of Justice, Motor Vehicle
Division. 2004 Edition. www. opi. mt/ gov/ pdf/ drivered/ manual/ ch6. pdf
This is Chapter 6 of 7 in the State of Montana’s Driver’s Manual for Obtaining a License to
Drive. The sub- heading for the Chapter states “ adverse driving conditions require additional
knowledge and skills,” which is noteworthy in and of itself as a stated assumption.
The chapter covers night driving, including a discussion of speed reduction, when to turn on
headlights; weather; road conditions including discussion of wet roads, fog, snow and ice;
driving emergencies including failed brakes, stuck gas pedals, running off the pavement,
vehicle becoming disabled, skidding and flat tire/ blowout.
The Chapter is very brief— 14 pages inclusive of a number of diagrams and a self- test— and
not particularly well organized. For example, the format of the headings and subheadings
make it difficult to determine if the chapter has moved on to a new topic or if a topic is
considered a part of the previous discussion. The discussion within each section of the
chapter is presented in a “ short sentence and bullet- point” format that provides little
description.
Beyond noting the topics included, this chapter is too brief and not broad enough to be
particularly well suited as a model for building the curriculum required under this project.
15
3) “ New Mexico Driver Education Curriculum, Unit 3: The Driving Environment, Chapter
9 Adverse Driving Conditions.” http:// ipl. unm. eud/ traf/ pubs/ DECurr/ chpp. pdf
This is Chapter 9 of 10 chapters making up the New Mexico Driver Education Curriculum.
Topics covered include weather conditions only – rain, mud, snow and ice, fog, dust storms
and glare. The Chapter is very brief ( 4 pages) and provides reference to NHTSA’s tips on
snow and winter driving.
Beyond noting the topics included, this chapter is too brief and not broad enough to be a
particularly useful model for the development of the driver education module required for
this project.
4) “ School Bus Driver In- Service Safety Series, Administrator Guide for Pupil
Transportation Supervisors, Adverse Conditions Module.”
http:// www. nhtsa. gov/ people/ injury/ buses/ UpdatedWeb/ topic_ 8/ agenda. html
Adverse conditions discussed include: slippery roads, limited visibility, vehicle control
problems, extreme temperatures, catastrophic conditions. Each is discussed in terms of what
causes the condition, what the driver should know about the condition, and how to handle the
condition. The module is very detailed and includes a detailed lesson plan and instructor
notes including slides and handouts.
Though the module is geared towards school buses, much of the subject matter is relevant,
although some topics, e. g. wind and how to handle passengers in extreme weather conditions
are geared towards school buses in particular. In addition, the format is potentially relevant
to the development of the driver education module envisioned for this project.
5) “ Texas Driver Education Classroom and In- Car Instruction Model Curriculum, Module
Eight Texas Driver Responsibilities: Adverse Conditions.” Texas Education Agency,
Texas Department of Public Safety, Texas Department of Transportation.
This is Module 8 out of 10 in the Texas Driver Education Classroom and In- Car Instruction
Model Curriculum. Topics covered include:
Visibility in Adverse Conditions – e. g. glare, darkness ( night- time driving), weather-related
visibility issues such as rain, fog, smoke, snow;
Extreme Weather Conditions – e. g. flash- flooding and low water crossings, extreme
temperatures, strong winds;
Protecting Occupants – e. g. seat belt use, airbag protection, proper steering wheel and
headrest adjustment, proper hand position;
Roadway and Vehicle Technology – e. g. intersections, guard rails, crash attenuators,
rumble strips, traffic calming devices, shoulders, medians, message signs, turn bay
lanes, anti- lock brakes, traction control devices, suspension control devices,
electronic stability/ active handling systems, crumple zones, door latches, glass,
headlights; and
Traction Loss Concerns – e. g. uneven road surfaces, wet leaves, rain or standing
water, ice and snow, mud, sand/ gravel, negative- banked curves.
16
The manual is quite detailed ( 60 pages in length) and includes description of module
prerequisites, time frames for coverage of information per topic and per activity/ discussion
within each topic, needed resources, instructor activities including accompanying
transparencies, worksheets, fact sheets and review sheets, videos, etc.
The objective of the module is stated as, “ The student appraises inclement and extreme
weather conditions and formulates predictions on vehicular and driver limitations before
developing and executing response; investigates roadway and vehicle technology including
occupant protection to develop an understating of the related uses as crash and injury
protections; demonstrates proper use of occupant protection devices and utilizes map reading
and route planning techniques to avoid adverse driving conditions.”
This document is detailed, well thought out and would be a good model for the type of driver
education module that could be developed under this project.
6) “ Curriculum Scope and Sequence Modules for Driver Education in Virginia, Module
Eight Driver Responsibilities: Adverse Conditions.” Virginia Department of Education
and Virginia Department of Motor Vehicles, August 2001.
The Virginia Module Eight appears to be exactly the same curriculum as that used by the
Texas Education Agency. The chapter covers the exact same topics as those listed above, in
the exact same order and detail, and references the same instructor activities including
accompanying transparencies, worksheets, fact sheets, review sheets and videos, etc. The
Virginia module does not, however, include a stated objective.
The assessment, therefore, is the same. This document is detailed, well thought out and
would be a good model for the type of driver education module that could be developed
under this project.
7) “ Driver Education Classroom and In- Car Curriculum, Unit 7 Environmental Conditions
That Affect Safe Vehicle Operation and Unit 8 Vehicle Functions and Malfunctions, and
Collision Reporting.” American Driver & Traffic Safety Education Association.
The “ Driver Education Classroom and In- Car Curriculum” was developed to provide current
information and techniques on teaching novice drivers the basics of motor vehicle operation.
It was designed to be used specifically with and references the following textbooks:
Drive Right. 10th edition. Prentice Hall
Handbook Plus. 1999 edition. Propulsion International, Inc.
How to Drive. 9th Edition. American Automobile Association
Responsible Driving. 2006 edition. Glencoe/ McGraw- Hill
The choice of text is left up to each individual school. The Curriculum is divided into 10
units and is designed to cover 45 hours of classroom instruction. Eight hours of in- car
instruction are grouped into the In- Car guide and alternative forms of the final exam are
provided along with unit exams.
17
Unit 7 is written to introduce students to the problems associated with driving under
conditions in inclement weather, limited visibility and limited traction. The Unit includes
reference to accompanying videos, slides and worksheets and also provides optional videos
to be presented with each subject. The goals of the Unit state that students should:
Participate in teacher- led discussion of the problems associated with driving at night,
in fog, rain, snow, smoke, not and cold temperatures and when there are strong cross
winds;
Complete worksheet 7.1, which asks how can each of sun glare, sunrise/ sunset, fog,
rain and snow affect a driver’s ability to see? What adjustments should a driver make
to better cope with the problem? What adjustments or checks other than driving, can
be made to help compensate for the condition?
Participate in teacher- led discussions of the advances in occupant protection,
including automotive technology designed to protect vehicle occupants or enhance a
driver’s ability to respond in the event of loss of traction or other emergency;
Participate in teacher- led discussion of traction and how it affects the movement and
control of your vehicle, how to detect and respond to various types of traction loss
and how to safely return to the paved roadway after drifting or steering onto the
shoulder; and
Complete Unit 7 test.
Unit 8 presents drivers with information about vehicle system functions and malfunctions
and what to do if involved in a collision. It is applicable to adverse conditions in that it
covers techniques used to respond to various vehicle malfunctions including loss of brakes
and tire blowouts.
The stated goals of the Unit are that the student should:
Participate in teacher- led discussion dealing with vehicle systems and system
malfunction;
Participate in teacher- led discussion on performance characteristics of various types
of vehicles;
Participate in teacher- led discussion on responding to various emergencies caused by
vehicle malfunctions;
Participate in teacher- led presentation on collision reporting requirements and
behavior at the scene of a collision; and
Complete Unit 8 test.
Although the two Units combined do not cover all of the topics included in the operational
definition of adverse conditions developed for this project, the two documents appear to have
some useful information in terms of serving as a model for the development of the driver
education module envisioned for this project.
18
8) “ Aware Driver Defensive Driving Course, Module 7 – Environmental Hazards & Vehicle
Emergencies,” www. awaredriver. com.
Sponsored by American Institute for Public Safety and designed and implemented by Improv
Traffic School, this instruction module is provided either on- line, through distance learning
( videos or Digital Video Discs ( DVDs)) or in four hour classroom formats. Improv offers
State and Court approved interactive traffic safety programs in many states. The curriculums
are designed to change students’ attitudes toward driving in order to become more
knowledgeable and responsible drivers. Improv’s approach is interactive and utilizes
entertainment values to present an educational message known as “ edu- tainment” and
reflective of the advent of such media as Music Television ( MTV) and interactive Compact
Discs read- only memory ( CD- ROMs) and DVDs. The primary focus of their program is
behavior modification related to traffic safety in order to reduce injuries and fatalities.
The Aware Driver Defensive Driving Course includes 10 Modules including:
Module 1 – Appropriate Attitude
Module 2 – Licensing Control & Actions
Licensing Control Measures
Canceled, Suspended & Revoked Licenses
Module 3 – Signals, Signs & Road Markings
Lane Use and Road Markings
Module 4 – Speeding
Basic Speed Law
Stopping Distances & Force of Impact
Module 5 – Sharing the Road
Turns & Special Lanes, Carpool lanes, Highways and City Streets
Module 6 – Crash Prevention
Defensive Driving Techniques
Passing
Collision
Financial Responsibility
Collision Case Reviews
Module 7 – Environmental Hazards & Vehicle Emergencies
Adverse Driving Conditions
Driving Emergencies
Module 8 – Safety Equipment & Vehicle Maintenance
Vehicle Maintenance
Passenger Restraints
Module 9 – Driving Under the Influence
Driving Under the Influence
DUI Penalties
Module 10 – Other Impairments
19
Module 7 includes discussion of adverse driving conditions and driving emergencies. The
adverse driving conditions portion of the module includes discussion of fog conditions, darkness,
and driving in the rain or on slick roads. The driving emergencies portion of the module includes
discussion of brake failure, fire, mechanical breakdown, right wheels going off the shoulder, gas
pedal sticking, power steering failure, tire blowouts, and hood flying up.
Though the coverage of the adverse conditions- related topics is not particularly detailed or broad,
the interactive, “ edu- tainment” format of this program is an interesting concept to consider in
terms of the possibility of incorporating some features in to a model curriculum for AzDOT.
Summary
In summary, a number of documents were reviewed that could serve as models for the module( s)
anticipated to be developed under this project. These documents provide both substantive
content- related information and useful ideas for format and instructional and delivery methods.
Specifically, the Virginia Department of Motor Vehicles and Texas Education Agency
documents provide detailed topical information and provide an organized layout and approach to
the presentation of the material. Similarly, the “ School Bus Driver In- Service Safety Series” and
the “ Driver Education Classroom and In- Car Curriculum” appear to have some useful content
that should be considered in the development of the module( s) for this project. Both the “ Aware
Driver Defensive Driving Course” and the “ Novice Driver Education Model Curriculum
Outline” provide useful guidance on instructional methods, methods of delivery and performance
objectives. The “ Aware Driver Defensive Driving Course” in particular provides unique
examples of interactive delivery methods and ways of utilizing entertainment values to present
an educational message.
2.3: Summary of Research on Issues Related to Adverse Driving Conditions and Driver
Education
This section presents a discussion of various issues related to the topic of adverse driving
conditions and driver education including review of national crash and crash cause statistics,
research on the impacts of driver education on crashes and highway safety policy issues in
general.
Crash Statistics
According to the AAA Foundation for Traffic Safety in a paper prepared in collaboration with
the Federal Highway Administration ( FHWA) and NHTSA, 7 traffic safety progress in the U. S.
has slowed considerably over the past dozen years. From 1992 to 2004, the traffic fatality rate
dropped 17 percent, from 1.75 per 100 million vehicle miles of travel to 1.46, and traffic injuries
dropped 9 percent, but total traffic fatalities increased by 9 percent. In contrast, over the
previous dozen years from 1980 to 1992, the fatality rate dropped 48 percent and total traffic
fatalities dropped 17 percent. In 2004, there were 1.46 traffic fatalities per 100 million vehicle
7 Traffic Safety Issues of the Future: A Long Range Research Agenda. AAA Foundation for Traffic Safety. January
2006.
20
miles, which translates into 42,636 fatalities in that year. The U. S. Department of Transportation
has the stated goal of reducing the rate of motor vehicle traffic fatalities to 1.0 per 100 million
vehicle miles traveled by 2008, or roughly 30,000 fatalities per year. As of 2007, it would
appear it is unlikely this goal will be achieved. In its Traffic Safety Facts 2005,8 NHTSA’s
National Center for Statistics and Analysis reports that deaths and injuries resulting from motor
vehicle crashes are the leading cause of death for persons of every age from 3 through 33 ( based
on 2003 data).
There are not many statistics available regarding the causes of crashes, especially as related to
the topic of this report ( e. g. adverse conditions), but NTHSA’s 2004 Traffic Safety Annual
Report does include a table on Crashes by Weather Condition, Light Condition and Crash
Severity. 9 The table reveals that 40 percent of all crashes in 2004 ( includes fatal crashes, injury
crashes and property- damage only crashes) occurred during non- daylight hours ( including dark
but lighted, dark or dawn/ dusk) and under some type of weather condition ( either rain,
snow/ sleet or other). Of rain, snow/ sleet and other, rain was the weather condition involved in
the greatest percentage of weather- involved crashes at 71 percent. Looking exclusively at the
lighting conditions of “ dark, but lighted” and “ dark and dawn/ dusk;” “ dark, but lighted” was the
lighting condition under which the greatest percentage of lighting- involved crashes occurred at
48 percent.
The only other research reviewed that included statistics on the causes of crashes concluded that
driver inattention is the leading factor in most crashes and near- crashes. 10 In this study, the
behaviors of the drivers of 100 vehicles equipped with video and sensor devices were tracked for
more than one year. The study concluded that nearly 80 percent of crashes and 65 percent of
near- crashes involved some form of driver inattention within three seconds before the event.
The primary causes of driver inattention identified in the study included cell phone use and
drowsiness.
In general, studies of actual driver behavior are difficult because of the complications associated
with data collection. Drivers may or may not accurately report on their own behavior when
asked after the fact, and there is the argument that drivers will not behave in the same manner as
they normally would if they know they are being monitored.
Two of four broad research areas requiring further study were crash causation data in particular
and crash data in general. 11 According to the participants in this workshop, the more that is
known about the causes of crashes, the more this knowledge can help develop and implement
crash avoidance countermeasures. Specific crash causation research issues identified included
those associated with highway and environment issues such as geometric design, crash location,
8 Traffic Safety Facts 2005 Data. DOT HS 810 623. National Highway Traffic Safety Administration ( NHTSA)
National Center for Statistics and Analysis.
9 Traffic Safety Facts 2004 A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System
and the General Estimates System. DOT HS 809 919, NHTSA National Center for Statistics and Analysis. Table
25.
10 The 100- Car Naturalistic Driving Study, NHTSA and Virginia Tech Transportation Institute ( VTTI), 2006.
11 Traffic Safety Issues of the Future: A Long Range Research Agenda. AAA Foundation for Traffic Safety, Federal
Highway Administration, National Highway Traffic Safety Administration. January 2006.
21
pavement ( friction) condition; and those associated with human factors such as distinguishing
causes by crash severity and driver demographics, and studying near crashes.
Efforts to help improve crash data collection include the Model Minimum Uniform Crash
Criteria Guidelines ( MMUCC) 12 developed as a collaborative effort of the NHTSA, FHWA, the
Federal Motor Carrier Safety Administration ( FMCSA) and the Governors Highway Safety
Association ( GHSA – formerly NAGHSR). The purpose of MMUCC is to provide a data set for
describing crashes of motor vehicles that will generate the information necessary to improve
highway safety within each state and nationally. MMUCC recommends voluntary
implementation of a “ minimum set” of standardized data elements to promote comparability of
data within the highway safety community. It serves as a foundation for state crash data systems
and was first recommended as a voluntary guideline in 1998. The Second Edition of MMUCC
( published in 2003) represents an update to this “ minimum set” of data elements in response to
emerging issues and other highway safety needs. The five new data elements added to the
Second Edition include: distracted drivers, special use vehicles, roadway information at the
vehicle level, hit and run crashes and vehicle contributing circumstances.
Impacts of Driver Education on Crashes
Though a subtle point, a general observation of the literature on the subject of driver education
impact on crashes is that almost all driver education curricula are geared towards novice drivers.
Consequently, most research on the impacts of driver education programs relate specifically the
impacts of these programs on novice drivers. So, though many studies have found driver
education to be ineffective in reducing crashes, they are really concluding that driver education is
ineffective in reducing crashes amongst novice drivers. In addition, many studies have
concluded that inexperience, not lack of skill, is the primary cause of novice driver crashes.
Consequently, a review of the literature makes it difficult to isolate the impact of driver
education on the actual behaviors of drivers in general, let alone on crashes.
This begs the question, would a driver education module on driving under adverse conditions
given to more experienced drivers be more effective than the same module presented to novice
drivers? The literature would suggest, yes, the outcome would be different because inexperience
is the biggest factor impacting crashes, not necessarily a lack of skill.
It is generally agreed in the literature that inexperience is the greatest contributor to crashes.
Novice drivers experience serious crash losses far beyond their representation in the driver
population or their proportion of mileage driven. 13 According to the AAA Foundation for Traffic
Safety, new drivers lack important skills, particularly those needed to acquire and process
information. They are not as effective as experienced drivers in scanning the environment,
recognizing potential hazards while they are still at a safe distance, and making difficult
decisions quickly. They tend to underestimate the danger of certain risky situations and
overestimate the danger in others.
12 “ Improving Crash Data for Safer Roadways, Model Minimum Uniform Crash Criteria Guideline ( MMUCC).”
Second Edition, 2003.
13 Novice Driver Education Module Curriculum Outline, AAA Foundation for Traffic Safety, 1995
22
Decades of research indicate that driver education does not reduce crash involvement among
beginning drivers. According to an Insurance Institute for Highway Safety article, 14 several
comprehensive international reviews of the best scientific evaluations of driver education
programs for novice drivers all came to the same conclusion: “ There is no difference in the crash
records of driver education graduates compared with equivalent groups of beginners who learned
to drive without formal education.” 15 Beyond this, the article concludes that there is also little
evidence that courses teaching advanced driving maneuvers such as skid control improve driver
safety, and further that these courses appear to actually increase rather than reduce the crash risk
of young males. Similarly, the AAA Foundation for Traffic Safety has found in other research, 16
that there is not much compelling evidence that young people who complete driver education
programs drive more safely or have fewer crashes than those who receive less formal driver
instruction.
According to the Insurance Institute’s article, the international driver education literature
summarizes the effects of driver education as follows:
“ The research literature suggests that, beyond imparting basic car control and road law
knowledge skills, pre- license driver training/ education contributes little to post- license
reductions in casualty crashes or traffic violations among novice drivers. In addition,
mandatory pre- license training or even formal pre- license training/ education, such as high
school driver education programs in the USA, may contribute to increase exposure- to- risk for
young drivers, particularly females, by encouraging early solo licensing. There is also
considerable evidence that driver training that attempts to impart advanced skills such as skid
control to learner drivers may contribute to increased crash risk, particularly among young
males. This pattern of results has been confirmed and replicated across numerous studies
conducted in Australia, New Zealand, North American, Europe and Scandinavia during the
last 30 years.” 17
The literature suggests that some reasons driver education has not historically produced safer
drivers include:
The courses are generally of short duration ( for example 30 hours in- class and six hour
in- vehicle) and can therefore only address basic driving skills;
14 Ferguson, S. A. and Williams, A. F. Driver Education Renaissance. Insurance Institute for Highway Safety, 2004.
15 Ferguson, S. A. and Williams, A. F. Driver Education Renaissance. Insurance Institute for Highway Safety, 2004
citing Christie R. The effectiveness of driver training as a road safety measure: a review of the literature. Victoria,
Australia: Royal Automobile Club of Victoria Ltd, 2001. and Mayhew DR, Simpson HM, Williams AF, et al.
Effectiveness and role of driver education and training in a graduated licensing system. J Public Health Policy
1998; 19: 51– 67 and Vernick JS, Li G, Ogaitis S, et al. Effects of high school driver education on motor vehicle
crashes, violations, and licensure. Am J Prev Med 1999; 16: 40– 6. and Woolley J. In- car driver training at high
schools: a literature review. Walkervillle, South Australia: Transport SA, Safety Strategy, 2000. and Roberts I,
Kwan I, Cochrane Injuries Group Driver Education Reviewers. School based driver education for the prevention of
traffic crashes ( Cochrane review). The Cochrane Library, Issue 1. Oxford, UK: Update Software Ltd, 2002.
16 Evaluating Driver Education Programs. AAA Foundation for Traffic Safety, August 2006.
17 Ferguson, S. A. and Williams, A. F. Driver Education Renaissance” Institute for Highway Safety, 2004 page 3
citing Christie R. The Effectiveness of Driver Training as a Road Safety Measure: A Review of the Literature.
Victoria, Australia: Royal Automobile Club of Victoria Ltd, 2001.
23
Driver education is primarily given to young, novice drivers who are experiencing on-going
peer, parental, personal and other social influences that shape their driving styles
and crash involvement more than the driver education they are receiving;
Driver education is primarily given to young, novice drivers who are typically
unmotivated by safety concerns, e. g. the goal of most driver education students is
learning enough skills to pass the driving test ( as opposed to learning the skills that will
make them a safe driver); and
Driver education is primarily given to young adolescents who typically possess
development and lifestyle features including risk taking, feelings of invulnerability, and
immature decision- making, all of which make it difficult to use safety messages in order
to influence the way they drive.
In Evaluating Driver Education Programs: Management Overview, 18 the AAA Foundation for
Traffic Safety highlights a key point in the general debate over driver education impact on traffic
safety, which is that how driver education is evaluated depends on the objectives chosen for that
education. For example, is the proper success criterion for driver education safer mobility or a
safer youth population? If road safety is the primary concern, that is, safer mobility, then crash
rates per miles driven could be an appropriate performance measure. If concerned primarily with
the overall safety of the youth population, crash rates per teen would be a more appropriate
measure. The article concludes that, while evaluation is important to improving the effectiveness
and efficiency of driver education, it is also important to recognize its limitations. “ Evaluation
of driver education, like driver education itself, is evolving and still has far to go” the article
maintains.
Despite these findings presented in the paragraphs above, the literature also suggests that there
are specific reasons driver education has failed in terms of reducing crashes and, more
importantly, that there are steps that can and should be taken to change that. For example, in the
opinion of the AAA Foundation for Traffic Safety, the main function of current driver education
is to support mobility, not to improve the safety performance of novice drivers. 19 In the
introduction to its paper, Driver Education: The Path Ahead, the Transportation Research
Board’s Operator Education and Regulation Committee says that, “ the failure of present- day
instruction to provide a convincing demonstration of its ability to reduce accidents establishes
the need for change.” 20 Views such as these, point to the need for research projects like the one
being undertaken by AzDOT. The AAA Foundation for Traffic Safety notes in its’ document,
Evaluating Driver Education Programs: Management Overview, that driver education is
changing rapidly due to graduated licensing and other factors. For example, in some
jurisdictions, such as Finland and Michigan, new drivers are required to take a second stage of
training after they have been driving as licensed drivers for a short period of time.
According to the AAA Foundation for Traffic Safety, if driver education is to produce safer
drivers it must reinforce the individual and community factors that positively influence personal
18 Evaluating Driver Education Programs: Management Overview. AAA Foundation for Traffic Safety. August
2006. Page 54.
19 Novice Driver Education Model Curriculum Outline. AAA Foundation for Traffic Safety, 1995.
20 Driver Education: The Path Ahead. Transportation Research Board, Operator Education and Regulation
Committee, Transportation Research Circular E- C101, August 2006.
24
motivation and social responsibility. In their opinion, “ knowledge of how to control a car is not
as critical to safety as individual motivation: Strong motivation makes up for weak skills better
than strong skills make up for weak motivation.” 21
The literature suggests that driver education can be made more effective in positively impacting
safety if it is coordinated with graduated licensing ( to combat the behaviors associated with
inexperience) and inclusive of advances in interactive learning technology. Specifically, for
example, the AAA Foundation for Traffic Safety makes the following recommendations: 22
Develop software for teaching and testing knowledge and skills in an individual, self-paced,
automated way.
Develop interactive multi- media units for training and testing driver attention and visual
detection as well as risk perception and evaluation.
Develop software based on game- theory models to diagnose, clarify, and reinforce
modification of new drivers' risk- taking styles and to demonstrate their consequences.
Develop improved in- car instruction and instrumentation to teach driving and perception
skills and provide feedback on driver performance.
Develop participative classroom units for peer- focused seminars, individual study
projects, and group work. These are needed to clarify health and safety values and to
enhance personal motivation and social responsibility.
Develop instructor training to support the use of new interactive media, participative
classroom units, and in- car perception units. The need is to reinvent the teacher and
instructor's role, enriching the job by shifting the emphasis from information provider to
that of coach or mentor for health and safety motivation, social values, and life skills.
Develop tools, models, and instruction units that support parent involvement in young
driver education.
Develop models and incentives that mobilize community, industry, and government
support for coordinating positive influences on novice drivers. These should include links
between the driver education and health promotion communities and between driver
education and insurance providers.
Coordinate development of graduated licensing systems with driver education. Move to
multi- stage education in the graduated licensing jurisdictions. These driver education
formats should also be pilot tested for effectiveness and market acceptance in non-graduated
jurisdictions.
Expand the integration of driver education topics into other school subjects, particularly
health, community service, and other values- related activities.
Following on the conclusion that education in coordination with graduated licensing is a way to
positively impact traffic safety, the Insurance Institute for Traffic Safety article cited earlier
suggests that education for parents, as the primary providers of supervision, could be effective.
The idea is that a coordinated approach including driver education for novice drivers, a
21 Novice Driver Education Model Curriculum Outline. AAA Foundation for Traffic Safety, 1995. page 3.
22 Ibid.
25
graduated licensing program that extends the learner period and is facilitated by parents guided
by professional instruction could produce safer drivers.
According to Raymond Peck in his paper Novice Training Effectiveness Evaluation, “ If driver
training is to have a measurable effect on crash rates, it should impact those intermediate or
mediating factors that are most highly associated with crash causation and which potentially are
modifiable through training.” 23 The paper goes on to identify such factors as search and scan
strategies, critical cue perception, and hazard recognition as being particularly critical to crash
avoidance.
The AAA Foundation for Traffic Safety notes in both Novice Driver Education Model
Curriculum Outline and Evaluating Driver Education Programs: Management Overview, that
driver education programs are given a tougher mission than most education programs in that they
are expected to produce improved driving and measurable reductions in crashes. Consequently,
the former article maintains, driver education programs should become a leader in participatory
education in the classroom and self- paced, automated training in the lab. The Foundation notes
that it is important to keep in mind the specific problems that driver education should help solve,
e. g. what is it about young drivers and their crash risk that we can actually expect education to be
able to change?
Highway Safety Policy Issues
The topic of this project is part of the larger public policy question as to what is the proper
course of action for the U. S. to take in terms of traffic safety. Is traffic safety a federal
government responsibility or a state- level issue? What methods have proven effective in
improving traffic safety from a policy standpoint? What levels of traffic safety are we as a
society willing to consider acceptable? How does the U. S. compare to other countries in their
approach to traffic safety and their achievements in improving it?
In his book, Traffic Safety, 24 Leonard Evans, a former General Motors research scientist and
current researcher, writer and lecturer on traffic safety and president of Science Serving Society,
compares the U. S. to other countries in terms of policies aimed at reducing traffic fatalities and
concludes that U. S. traffic safety policy has been a “ dramatic failure.” 25 Looking at three traffic
fatality rates – fatalities per year ( the raw fatality rate), fatalities per 1,000 registered vehicles
( the vehicle rate), and fatalities per 100 million vehicle- miles of travel ( the distance rate) – Evans
demonstrates that there has been a decline in U. S. safety relative to other countries over the
period 1972 to 2002. The book acknowledges that the declines achieved in fatality rates in the
U. S. when viewed absent of the comparison to other countries appear impressive, but uses the
comparison to make the point that changes in U. S. policies enacted in the mid- 1970s made the
U. S. fall behind other countries in terms of the percentage declines in fatality rates that could
have been achieved had the U. S. followed similar policy actions.
23 Driver Education: The Path Ahead. Transportation Research Board, Operator Education and Regulation
Committee, Transportation Research Circular E- C101, August 2006, page 13.
24 Evans, Leonard. Traffic Safety. ( Science Serving Society, Bloomfield Hills, Michigan). 2004.
25 Evans, Leonard. The Dramatic Failure of U. S. Traffic Safety Policy: Engineering is Important, Public Policy is
Crucial. Signals: TR News 242. January- February 2006.
26
Evans maintains that public policy aimed at driver behavior can and does make a difference.
More specifically, Evans contends that U. S. policy has focused on vehicle factors – even those
factors that research has shown are of minor importance in terms of crash causation – while
largely ignoring policies aimed at road- user behaviors, which research has shown to be effective
in reducing crashes. The road- user behaviors that Evans believes can be impacted through
appropriate policy actions include speeding, alcohol use, traffic law violation and belt wearing.
Evans contends that the U. S. has wrongly focused on improving survivability from crashes ( e. g.
through the use of airbags and other vehicle technologies) in order to achieve ground
transportation safety improvements instead of on preventing crashes.
Brian O’Neill, President of the Insurance Institute for Highway Safety and the Highway Loss
Data Institute, chronicles traffic fatality rates and Federal and state traffic safety legislation from
the late 1960s through 2004 in his article Improving U. S. Highway Safety, Have We Taken the
Right Road? 26 O’Neill takes the stance that the 42,000 deaths from crashes each year is too big a
price to pay for personal mobility. He documents in his article that in the 1960s and 1970s, the
U. S. established federal motor vehicle safety standards, issued standards to address road user
issues at the state level ( e. g. driver licensing requirements, motorcycle helmet use and
countermeasures for alcohol- impaired driving), and at the same time established standards for
new road construction. O’Neill states, “ In the 1970s federally mandated countermeasures
addressed problems related to road users, vehicles and the road environment, and more
countermeasures were expected.” Then in 1975, Congress overturned the legislation authorizing
the federal mandates for road user behavior, eliminating the federal government’s ability to
coerce states, through the withholding of federal highway construction funds, to establish
effective programs and laws addressing road user behavior. As an example of a negative impact,
O’Neill demonstrates the effect this policy action had on the number of states with universal
helmet laws from 1966 to 2005 – a number that fell from 47 states in 1975 to 20 states in 2004.
O’Neill notes in the article that two portions of the federal highway safety program – NHTSA
and FHWA – have remained in place and have been generally successful in continuing to
address vehicle and road design safety issues, respectively, at the federal and state level. The
article acknowledges that even without federal requirements to address road user issues – seat
belt use, speeding and alcohol- impaired driving – the U. S. has realized some successes in these
areas. He points out, however, that though policy makers tend to recognize scientific measures
to determine which countermeasures work and which do not for vehicle designs and for road
designs, e. g. the physics, engineering and biomechanics are well understood, they appear to
ignore the scientific evidence related to countermeasures aimed at road user behavior. Different
science disciplines are involved, but there are scientific measures available for determining
which road user behavior countermeasures are more and which are less effective in reducing
traffic fatalities. The article uses driver education as an example stating that even though many
studies have shown education by itself rarely changes road user behavior, many decision- makers
continue to maintain that more education is all that is needed.
O’Neill takes issue with Evans’ claim that this history of federal legislation represents a
“ dramatic failure” in U. S. safety policy, but rather that it demonstrates a dramatic failure in the
26 O’Neill, Brian. Improving U. S. Highway Safety, Have we Taken the Right Road? Signals. TR News 239. July-
August 2005.
27
safety policy of some states, pointing out that many states in the U. S. have fatality rates that meet
or exceed the comparative rates of the other countries Evans uses in his comparisons. Evans, in
response, maintains in his book that this fact merely emphasizes his underlying point that public
policy aimed at driver behavior really does make a difference. O’Neill concludes that progress
on road user issues in the U. S. will depend on political action at the state level.
In his article, Eliminating the Annual Highway Safety Tragedy, 27 Samuel C. Tignor agrees with
O’Neill’s assessment that State DOTs and local agencies must be more proactive in addressing
highway safety problems and implementing proven safety infrastructure countermeasures.
Tignor states in his article that there have been few attempts to bring national attention to the
highway safety problem in the U. S. and that, “ The primary safety problem in the United States is
the lack of commitment to solve the problem.”
Specifically, Tignor believes state DOTs and local agencies need to:
Sensitize field staff and managers to find, report, and eliminate safety problems;
Increase public awareness of safety by publishing the portion and the amount of
improvement project funds that are spent on safety enhancements;
Demonstrate that many safety solutions are simple and inexpensive; and
Require highway safety impact studies for all highway projects.
Tignor agrees with the Evans argument that too much of the highway safety emphasis in the U. S.
has been placed on surviving crashes as opposed to preventing crashes. He notes as a deficiency
in both the Evans and O’Neill arguments that neither mentions that 25 percent of highway
crashes relate to interaction problems between users and highway features. Tignor maintains that
eliminating these problems alone could reduce fatalities by more than 10,000 annually.
Generally, Tignor believes that, “ The systematic use of engineering oversight, safety audits and
human factors analyses can identify many problems and lead to simple and inexpensive
corrections.”
In conclusion, like many other public policy issues, there are a variety of solutions to increase
traffic safety. It comes down to societal goals and societal acceptance of those various options.
For example, how many fatalities are acceptable? Depending on the answer to that question, the
U. S. could be considered either successful or unsuccessful in its approach to traffic safety. What
types of countermeasures will drivers ( and consequently elected officials and vehicle
manufacturers) find palatable and which will be deemed unacceptable given our societal desire
for increased mobility? For example, manufacturers could certainly build vehicles and the
government – federal or state – could mandate that manufacturers must build vehicles that do not
go over a certain speed, or that do not operate without a safety belt engaged or that do not
operate before performing an alcohol “ breathalyzer” test, but would we as a society find that
acceptable? Should we be focusing on the cost- effectiveness of various solutions? Certainly the
above stated examples would be cheaper than implementing long- term, nationwide belt- law
publicity campaigns and enforcement measures, but is cost- effectiveness our primary goal?
27 Tignor, Samuel C. Eliminating the Annual Highway Safety Tragedy. Point of View. TR News 245. July August
2006.
28
Public policy always has to consider the cost effectiveness of various solutions and weigh that
against societal goals, objectives and tolerances. Highway safety issues are no different. In
order to be able to perform this type of analysis, data must be available to support it. In addition,
methods and technologies are constantly evolving that impact this available data. This is why
continued research is always essential and why projects such as the one being undertaken by
AzDOT are so important.
29
CHAPTER 3: STATISTICAL ANALYSIS OF ARIZONA ACCIDENT DATA
The purpose of this chapter is to provide the results of a statistical study of Arizona crash data.
This statistical analysis was conducted for two purposes:
1) To extract information relative to crashes under adverse driving conditions; and
2) To analyze the data to ascertain whether driver training might have reduced the frequency
or severity of these crashes.
This chapter is divided into the following five sections:
Section 3.1 reviews the Arizona crash data. This includes a review of the data collection forms,
the crash database used in this study and the annual publication “ Arizona Crash Facts.”
Section 3.2, describes the methodology used in the statistical analysis. Included is a description
of the time period covered, a review of the definition of adverse conditions that is used, a review
of the definition of driver education indicators that is used, and an overview of the data sorts that
were developed.
Section 3.3 presents the data on the extent of accidents and fatalities involving adverse driving
conditions. Included is an analysis of the number of accidents and fatalities by type of adverse
condition and a summary of the total extent of accidents involving adverse conditions. Detailed
data for 2005 is presented along with summary time- series data.
Section 3.4 presents data on the extent of accidents and fatalities involving adverse driving
conditions where there is also an indicator that driver training might have reduced the frequency
or severity of these crashes. Included is an analysis of the number of accidents and fatalities by
type and a summary of the total extent of accidents involving both adverse conditions and an
indicator that driver training might have reduced the frequency or severity. Detailed data for
2005 is presented along with summary time- series data.
Section 3.5 provides conclusions based on the statistical analysis and recommendations for
further analysis.
3.1: Arizona Crash Data
Statistical data on motor vehicle crashes in Arizona are compiled from Arizona Traffic Accident
Reports submitted to the Arizona Department of Transportation by state, county, city, tribal, and
other law enforcement agencies. Within the Arizona Department of Transportation, the Arizona
Traffic Accident Reports are compiled by the Traffic Records Section, Motor Vehicle Crash
Statistics Unit. The Arizona Department of Transportation’s Motor Vehicle Division publishes
an annual statistical review of the motor vehicle crashes in the State of Arizona. This publication
is known as the Motor Vehicle Crash Facts for the State of Arizona. 28 In order to provide the
most current information, preliminary data is utilized when necessary. For this reason, previous
28 Motor Vehicle Crash Facts for the State of Arizona, Arizona Department of Transportation, Motor Vehicle
Division, http:// www. azdot. gov/ mvd/ statistics/ crash/ index. asp.
30
or future reports differ slightly. For example, the number of accidents and fatalities reported in
this analysis are slightly different than the published estimates, although the differences are quite
small. For example, the numbers of fatalities agree exactly in three of the five years and differ
by only 3 and 4 in 2003 and 2005, respectively
Exhibit 3- 1 provides a summary table from the 2005 Crash Facts, which was the most recent
version available for the purposes of this study. Both the number of crashes and the number of
fatalities have increased over the period 2001 to 2005, although the pattern was uneven, with a
decline in 2003.
Exhibit 3- 1: Summary Table from the 2005 Arizona Crash Facts
Year Total
Crashes
Fatal
Crashes
Injury
Crashes
Property
Damage
Crashes
Total
Persons
Killed
Total
Persons
Injured
Total
Licensed
Drivers
Total
Registered
Vehicles
2001 131,899 944 46,234 84,726 1,057 74,110 3,550,765 4,031,359
2002 134,228 984 46,209 81,045 1,132 14,2: 30 3,668,104 4,089,002
2003 130,895 911 45,117 84,147 1,11B 11,001 3,819,823 4,193,262
2004 138,547 990 46,674 00,883 1,151 73.415 3,784,365 4,364,851
2005 139,265 1,038 45,361 92., 800 1,119 10,293 3,963,005 4,556,448
The data used in this study were provided by the Arizona Department of Transportation in five
separate Microsoft Access databases, one for each of the years 2001- 2005. For the purposes of
this study, the data in each year were provided in four primary tables:
1) Incident;
2) Traffic Unit;
3) Vehicle; and
4) Person.
There is one Incident record per accident. There is one Traffic Unit record per unit involved in
the accident ( this can include non- vehicles). There is one Vehicle record per Traffic Unit, except
when a traffic unit is not a motor vehicle. Finally, there is one Person record per person involved
in the accident. For purposes of this study, the analysis of Traffic Units was limited to vehicles
and Person records were limited to drivers. These restrictions do not affect the count of injuries
and fatalities since these are recorded in the Incident table.
In order to process and tabulate the data for this study, two tables were created for each year,
with each containing only the relevant data. The tables are:
The Adverse Condition Incidents Table – This table contains each reported adverse
condition for each driver in each incident. Incident- level conditions, such as road
condition, are reported once for each vehicle involved.
31
The Education Indicator Incidents Table – This table contains each reported education
indicator for each driver in each incident.
These tables were created using a query that was added to the databases. These macros
are important because a variety of adjustments were made to the data mainly due to the
complication that the data fields are reported at various levels ( Incident, Traffic Unit,
Vehicle, and Person). For example, the macros used for the 2005 data included the
following:
o AZDOT_ 2005. AdverseConditions. Count of Occurrences, Unadjusted – In this
macro each adverse condition is counted once for each time it is associated with a
vehicle in an incident ( accident). Since some conditions are associated with
incidents rather than vehicles, those incidents are counted by a multiple of the
number of vehicles in the accident.
o AZDOT_ 2005. AdverseConditions. Count of Occurrences, Adjusted - In this
macro conditions that are associated with vehicle or driver are counted once per
vehicle, conditions associated with the incident are counted once per incident.
AZDOT_ 2005. AdverseConditions. Count of Incidents - In this macro all conditions are
counted once per incident.
AZDOT_ 2005. AdverseConditions. Count of Fatal Occurrences, Unadjusted - In this
macro each adverse condition is counted once for each time it is associated with a vehicle
in an incident ( accident). Since some conditions are associated with incidents rather than
vehicles, those incidents are counted by a multiple of the number of vehicles in the
accident. Includes only incidents involving fatalities.
AZDOT_ 2005. AdverseConditions. Count of Fatal Occurrences, Adjusted - In this macro
conditions that are associated with vehicle or driver are counted once per vehicle,
conditions associated with the incident are counted once per incident. Includes only
incidents involving fatalities.
AZDOT_ 2005. AdverseConditions. Count of Fatal Incidents - In this macro all conditions
are counted once per incident. Includes only incidents involving fatalities.
AZDOT_ 2005. AdverseConditions. Count of Fatalities - In this macro fatalities are
counted once per incident, per adverse condition.
AZDOT_ 2005. Education_ PivotTable - In this macro a cross- tabulation of Adverse
Conditions and Education Indicators is developed. Each count represents the number of
vehicles for which the adverse condition and the education indicator were true. Incident-level
conditions are counted multiple times when multiple vehicles are involved. The
totals for the rows and columns are adjusted to represent unique incidents ( accidents) for
each factor. However, these totals still result in multiple counting of incidents since an
incident can have multiple factors in either the adverse condition category and/ or the
32
education indicator category. The grand total in the pivot table represents the unique
number of incidents involving any adverse condition and any education indicator.
AZDOT_ 2005. Education_ PivotTable_ Fatal - In this macro a cross- tabulation of Adverse
Conditions and Education Indicators is created for fatal accidents only. This is similar to
the previous tabulation but is for fatal accidents only. An additional outermost column
and row represents number of fatalities for each category.
3.2: Methodology
This subsection describes the methodology used in the statistical analysis. Included is a
description of the time period covered, a review of the definition of adverse conditions that is
used, a review of the definition of driver education indicators that is used, and an overview of the
data sorts that were developed.
Time Period Analyzed
The Arizona crash data is maintained in yearly files and 2005 data became available in mid-summer
of 2006. In order to process the data, one question that was addressed was the time
period to be analyzed. Since recent data are the most relevant data, it was determined that the
data for 2005 were the most important for the study. However, it was also determined that it
would be relevant to examine how adverse driving condition related accidents are changing. It
was also possible that there is a significant difference in the prevalence of accidents in different
years. As a result, it was determined that it would improve the analysis of the data to include
multiple years. Therefore, data were analyzed for a full five year period including 2001, 2002,
2003, 2004 and 2005. This use of a five year time period is consistent with the historical data
presented in the Arizona Crash Facts publication.
Definition of Adverse Conditions
The Literature Review provided in Chapter 2 of this report included a proposed definition for
“ adverse driving conditions” to be used for this project. Chapter 2 also presented a definition of
“ adverse driving conditions” operationalized in terms of the Arizona State Crash Forms.
According to the literature review, the fields of data shown in Exhibit 3- 2 were proposed and
accepted as the basis for the definition of adverse conditions. If any incident was coded on the
crash form and in the database as involving one or more of the following conditions it was
defined as involving “ adverse driving conditions.”
33
Exhibit 3- 2: Adverse Condition Data Fields
Variable Data Field
16 Light Condition 16.2 Dawn or dusk
16.3 Darkness
17 Weather Condition 17.3 Sleet/ hail
17.4 Rain
17.5 Snow
17.6 Severe Crosswinds
17.7 Blowing Sand, Soil, Dirt, Snow
17.8 Fog, Smog, Smoke
22 Unusual Road Condition 22.1 Under Construction, Traffic Allowed
22.2 Under Construction, No Traffic Allowed
22.3 Under Repairs
22.4 Holes, Ruts, Bumps
22.5 Obstruction, Protected
22.6 Obstruction, Unprotected
22.7 Obstruction, Unlighted at Night
22.8 Defective Shoulders
22.9 Changing Road Width
22.10 Water ( Standing or Moving)
22.11 Temporary Lane Closure
Road Surface Condition 26.2 Wet
26.3 Sand, Mud, Dirt, Oil, Gravel
26.4 Snow
26.5 Slush
26.6 Ice
Vehicle Condition 29.2 Defective Brakes
29.3 Defective Steering
29.4 Defective Headlights
29.5 Defective Tail Lights
29.7 Puncture or Blowout
29.8 One or More Smooth Tire
29.10 Defective Windshield Wiper
Vision Obscurement 31.10 By Headlight
31.11 By Sun Glare
31.12 Because of Bad Weather
31.14 Rain, Snow, Fog on Windshield
31.15 Windshield obscured - Other
Sort of Data by Type of Adverse Condition
The first sort of the data was designed to provide a compilation of accident data for each of the
adverse conditions. For example, data were developed on the number of accidents where the
item ( 16 Light Condition - 16.2 Dawn or dusk) was checked on the accident report. It was also
determined that it would be useful to tabulate data on the number of fatalities where the item was
34
checked. In addition, a control total on the number of accidents and number of fatalities in the
year was developed. This allowed for the calculation of the percent of accidents that involved a
dawn or dusk light condition. As described above, data were developed for each of five years.
Totals for All Adverse Conditions
One shortcoming of the first sort is that many accidents could involve more than one adverse
condition. For example, an accident could occur with the boxes checked for ( 16 Light Condition
- 16.2 Dawn or dusk), ( 17 Weather Condition - 17.3 Sleet/ hail), and ( 26 Road Surface Condition
- 26.2 Wet). It is certainly possible for an accident to occur at dusk with sleet falling on a wet
road.
Therefore, in this sort, data were developed for the number of accidents that occurred where any
of the adverse driving conditions were present. As described above, it was determined that it
would also be useful to have data on the number of fatalities and that data be developed for each
of five years.
Definition of Driver Education Indicators
As described in the introduction to this Chapter, the purpose of this task is not only to analyze
information relative to crashes under adverse driving conditions, but also to ascertain whether
driver education might have reduced the frequency or severity of these crashes.
Unfortunately for the purposes of this study, the Arizona State Crash Forms do not contain an
entry by the police officer indicating that driver education might have reduced the frequency or
severity of the accident. However, a thorough review of the Arizona State Crash Forms
uncovered a large number of variables that identified dangerous characteristics of the driver, the
drivers behavior or vehicle condition. In these situations it can be argued that there is at least an
indication that driver training would be a potential solution. 29 The data fields shown in Exhibit
3- 3 were considered to meet these conditions.
In addition to these items, it was recognized that driver training is often seen as especially
important and targeted toward two age groups, younger and older drivers. As a result, the
“ Date of Birth” field on the Arizona State Crash Forms was used to develop an indicator as to
whether younger or older drivers were involved in the accident and, therefore, whether driver
education might have reduced frequency or severity. Based on the literature review and Exhibit
3- 4, which shows the U. S. Vehicular Deaths per 100,000 People by Age, it was determined that
the age cutoffs should be 25 and under and 75 and over. At these ages, the fatality rate was
about 25 percent higher than the rates between 30 and 70 years old.
29 It was suggested by a member of the TAC that driving under the influence should not be considered an indicator
that driver education could reduce the number or severity of accidents involving adverse driving conditions.
However, it is observed that it is an established practice to require drivers convicted of driving under the influence to
participate in a driver education program. Therefore, it is presumed that driver education could impact a person’s
ability to avoid driving under the influence and improve his or her ability to respond to adverse driving conditions or
to improve his or her ability to respond to adverse conditions despite his or her impairment.
35
Exhibit 3- 3: Driver Education Data Fields
Variable Data Field
27 Conditions Influencing Driver 27.2 Had Been Drinking
27.3 Use of Illicit Drugs
27.4 Illness
27.5 Fell Asleep / Fatigued
27.7 Prescription Drugs
28 Violations/ Behavior 28.2 Speed Too Fast for Conditions
28.3 Exceeded Lawful Speed
28.4 Failed to Yield Right- of- way
28.5 Followed Too Closely
28.6 Ran Stop Sign
28.7 Disregarded Traffic Signal
28.8 Made Improper Turn
28.9 Drove on Opposing Traffic Lane
28.10 Knowingly Operated With Faulty or Missing Equipment
28.11 Required Motorcycle Safety Equipment Not Used
28.12 Passed in No Passing Zone
28.13 Unsafe Lane Change
28.14 Other Unsafe Passing
28.15 Inattention
Figure 3- 4: U. S. Vehicular Deaths per 100,000 People by Age, 2002
Graphic Courtesy of the Chicago Tribune as reprinted at http:// journeysafe. org: 80/ JourneySafe/ index. asp
36
It was therefore determined that the presence of one of the variables that identified dangerous
characteristics of the driver or the driver's behavior or the presence of a driver 25 or under or 75
and over, become the definition of a “ driver training indicator.” An accident involving any one of
these driver or age conditions are considered an indicator that driver training might have reduced
the frequency or severity.
Sort of the Impact of Driver Education on Individual Adverse Conditions
In this sort, data were developed for a cross- tabulation. Data were sorted to provide a compilation
of the number of accidents for each of the adverse conditions where one of the driver education
indicators including age (≤ 25 or ≥ 75) was also checked. For example, data would be provided on
the number of accidents where the item ( 16 Light Condition - 16.2 Dawn or dusk) was checked on
the accident report while at the same time the item ( 27 Conditions Influencing Driver - 27.2 Had
Been Drinking) was checked.
It was also determined that it would be useful to tabulate data on the number of fatalities and that
data be developed for each of five years.
Impact of Driver Education on All Adverse Conditions
As was the case with the sort of adverse conditions, one shortcoming of the combined sort of
adverse conditions against driver education indicators is that many accidents could involve more
than one adverse condition and more than one driver training indicator. For example, an accident
could occur with the boxes checked for ( 16 Light Condition - 16.2 Dawn or dusk), ( 17 Weather
Condition - 17.3 Sleet/ hail), and ( 26 Road Surface Condition - 26.2 Wet) as well as ( 27 Conditions
Influencing Driver - 27.2 Had Been Drinking), and ( Under 25). It is certainly possible for an
accident to occur at dusk with sleet falling on a wet road where the driver had been drinking and
was under 25.
Therefore, in this sort, data were developed for the number of accidents that occurred where any of
the adverse driving conditions and any of the driver training indicators including age (≤ 25 or ≥ 75)
were present. Note that there would have to be at least one of the conditions required for each of
the two groups of indicators. The total of these observations would represent the best available
estimate of the number of accidents involving adverse conditions where driver education might
have reduced the frequency or severity.
As described above, it was again determined that it would be useful to have data on the number of
fatalities and that data be developed for each of five years.
3.3 Accidents and Fatalities Involving Adverse Driving
As stated above, one purpose of this chapter is to provide the results of a statistical analysis of
information relative to crashes under adverse driving conditions. Exhibit 3- 5 summarizes the
number of incidents ( accidents) that involved each of the various adverse conditions identified in
the literature review and Exhibit 3- 2. Included is a percentage that indicates the percent of all
37
incidents for which that adverse condition was reported for the incident or at least one driver
involved in that incident. 30 Data are provided for each of the years 2001 through 2005.
Exhibit 3- 5: Number and Percent of Incidents by Type of Adverse Condition ( 2001- 2005)
2001 2002 2003 2004 2005
Condition # % # % # % # % # %
Dawn or Dusk 6,914 5.24 6,816 5.05 6,669 508 7,317 5.28 7,904 5.65
Darkness 30,935 23.43 31,539 23.38 30,759 23.45 32,371 23.35 31,995 22.89
Sleet/ Hail 1,055 0.80 322 0.24 288 0.22 211 0.15 229 0.16
Rain 4,973 3.77 3,078 2.28 5,302 4.04 6,109 4.41 5,780 4.13
Snow 1,058 0.80 672 0.50 601 0.46 923 0.67 571 0.41
Severe
Crosswinds 98 0.07 155 0.11 125 0.10 131 0.09 80 0.06
Blowing Sand,
Soil, Dirt, Snow 106 0.08 191 0.14 122 0.09 128 0.09 78 0.06
Fog, Smog,
Smoke 68 0.05 73 0.05 91 0.07 67 0.05 38 0.03
Under
Construction,
Traffic Allowed
3,877 2.94 4,463 3.31 3,700 2.82 3,346 2.41 3,301 2.36
Under
Construction,
Traffic Not
Allowed
92 0.07 98 0.07 69 0.05 73 0.05 98 0.07
Under Repairs 138 0.10 120 0.09 82 0.06 91 0.07 99 0.07
Holes, Ruts,
Bumps 372 0.28 352 0.26 358 0.27 308 0.22 311 0.22
Obstruction
( protected) 45 0.03 35 0.03 41 0.03 30 0.02 33 0.02
Obstruction
( unprotected) 120 0.09 124 0.09 102 0.08 118 0.09 104 007
Obstruction
( unlighted at
night)
113 0.09 112 0.08 130 0.10 144 0.10 112 0.08
Defective
Shoulders 29 0.02 22 0.02 38 0.03 36 0.03 41 0.03
Changing Road
Width 359 0.27 299 0.22 357 0.27 289 0.21 275 0.20
Flooded 453 0.34 363 0.27 495 0.38 499 0.36 489 0.35
Temporary Lane
Closure 463 0.35 465 0.34 356 0.27 380 0.27 353 0.25
Wet 7,515 5.69 4,529 3.36 7,558 5.76 8,655 6.24 8,124 5.81
30 One comment submitted by a member of the TAC noted that indicators/ variables that relate to crashes might be
underreported on crash report forms.
38
Exhibit 3- 5: Number and Percent of Incidents by Type of Adverse Condition ( 2001- 2005)
2001 2002 2003 2004 2005
Condition # % # % # % # % # %
Sand, Mud, Dirt,
Oil or Gravel 939 0.71 823 0.61 744 0.57 743 0.54 648 0.46
Snow - on road 713 0.54 320 0.24 331 0.25 553 0.40 359 0.26
Slush 215 0.16 112 0.08 108 0.08 172 0.12 195 0.14
Ice 1,162 0.88 840 0.62 539 0.41 568 0.41 460 0.33
Defective Brakes 1,065 0.81 998 0.74 938 0.72 955 0.69 941 0.67
Defective
Steering 193 0.15 199 0.15 162 0.12 164 0.12 159 0.11
Defective
Headlights 60 0.05 72 0.05 61 0.05 75 0.05 74 0.05
Defective Tail
Lights 88 0.07 76 0.06 70 0.05 66 0.05 71 0.05
Puncture or
Blowout 1,165 0.88 1,396 1.03 1,284 0.98 1,239 0.89 1,110 0.79
One or More
Smooth Tires 152 0.12 147 0.11 147 0.11 164 0.12 126 0.09
Defective
Windshield Wiper 32 0.02 26 0.02 21 0.02 20 0.01 16 0.01
Headlight Glare 104 0.08 99 0.07 95 0.07 95 0.07 72 0.05
Sun Glare 1,414 1.07 1,416 1.05 1,248 0.95 1,406 1.01 1,309 0.94
Because of Bad
Weather 292 0.22 241 0.18 260 0.20 279 0.20 256 0.18
Rain, Snow, Fog
on Windshield 424 0.32 290 0.21 392 0.30 474 0.34 418 0.30
Windshield
Obscured, Other 119 0.09 107 0.08 90 0.07 99 007 107 0.08
One of the most salient features of Exhibit 3- 5 is that the number and percentage of incidents
involving the various adverse conditions are fairly stable from year- to- year. Approximately
31,000 to 32,000 incidents representing about 23 percent of all incidents involve driving during
darkness. This is by far the largest of the adverse conditions. Three additional adverse
conditions: dawn or dusk, rain, and wet roads appear in about four to six percent of incidents.
“ Under construction with traffic allowed” is another major category of adverse condition and is
present in about two to three percent of incidents. Only eight of the remaining 31 categories
account for even a half of a percent of incidents in any given year and none of these eight items
account for more than 1.07 percent of incidents. These include:
Sleet/ Hail
Snow
Sand, Mud, Dirt, Oil or Gravel
Snow on Road
Ice
Defective Brakes
Puncture or Blowout
Sun Glare
39
Note that one or more of these adverse conditions may be present at a given incident. Exhibit 3-
6 summarizes overall data on the number of incidents, vehicles involved, and incidents involving
one or more adverse condition. Over the period from 2001 to 2005, the number of incidents
ranged from 131,000 to 140,000 and, involving 247,000 to 269,000 vehicles. Of these incidents,
50,000 to 53,000 involved one or more adverse condition representing between 36.9 and 39.1
percent. Again, the level of both incidents and incidents involving adverse conditions were
relatively stable from year- to year.
2001 2002 2003 2004 2005
Number of Incidents 132,042 134,893 131,171 138,645 139,789
Number of Vehicles in all Incidents 248,862 254,241 246,939 262,023 268,795
Incidents With One or More Adverse
Conditions 51,573 49,768 49,835 52,600 51,659
Percent 39.1 36.9 38.0 37.9 37.0
Incidents With One or More Education
Indicators 117,507 119,999 116,748 123,405 124,691
Incidents With One or More Adverse
Conditions and Education Indicators 44,409 42,601 43,030 45,441 44,863
Percent 33.6 31.6 32.8 32.8 32.1
Exhibit 3- 6: Number of Incidents ( 2001- 2005)
Exhibit 3- 7 summarizes the percent of incidents involving adverse conditions. As discussed
above, this percentage ranges from 36.9 and 39.1 percent and is relatively stable from year- to year.
39.1 36.9 38.0 37.9 37.0
0
5
10
15
20
25
30
35
40
Percent
2001 2002 2003 2004 2005
Exhibit 3- 7: Percent of Incidents with Adverse
Conditions
Similar data was also developed for fatalities under adverse driving conditions. Exhibit 3- 8
summarizes the number of fatalities that involved each of the various adverse conditions. Included
is a percentage that indicates the percent of all fatalities for which that adverse condition was
reported for the incident or at least one driver involved in that incident. Data are provided for
each of the years 2001 through 2005. The year- to- year stability that was evident for incidents is
less pronounced for fatalities due mainly to the lower number of observations. Once again,
darkness is by far the most prevalent of the adverse conditions and is even more pronounced for
fatalities at 44 to 49 percent of the incidents involving adverse conditions. The four additional
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adverse conditions: dawn or dusk, rain, wet roads and Under construction with traffic allowed;
which accounted for between two to six percent of incidents are again important for fatalities, but
are joined by Puncture or Blowout. Only ten of the remaining categories account for even a half of
a percent of incidents in any given year and none of these eight items account for more than 1.24
percent of incidents. These include:
Sleet/ Hail
Snow
Blowing Sand, Soil, Dirt, Snow
Holes, Ruts, Bumps
Flooded
Sand, Mud, Dirt, Oil or Gravel
Ice
Defective Brakes
One or More Smooth Tires
Sun Glare
Bad Weather
Compared to incidents, Snow on Road was the only adverse condition to fall off this list while
five new adverse conditions were added including:
Blowing Sand, Soil, Dirt, Snow
Holes, Ruts, Bumps
Flooded
One or More Smooth Tires
Bad Weather
Exhibit 3- 8: Number and Percent of Fatalities by Type of Adverse Condition ( 2001- 2005)
2001 2002 2003 2004 2005
Condition # % # % # % # % # %
Dawn or Dusk 57 5.39 79 6.98 92 8.21 66 5.73 75 6.34
Darkness 513 48.53 508 44.88 490 43.71 504 43.79 536 45.31
Sleet/ Hail 12 1.14 3 0.27 2 0.18 1 0.09 9 0.76
Rain 28 2.65 19 1.68 22 1.96 51 4.43 37 3.13
Snow 5 0.47 4 0.35 8 0.71 4 0.35 7 0.59
Severe Crosswinds 2 0.19 2 0.18 4 0.36 4 0.35 2 0.17
Blowing Sand, Soil,
Dirt, Snow 2 0.18 4 0.36 7 0.61 2 0.17
Fog, Smog, Smoke 1 0.09 1 0.09
Under Construction,
Traffic Allowed 21 1.99 11 0.97 20 1.78 8 0.70 15 1.27
Under Construction,
Traffic Not Allowed
Under Repairs 1 0.09 2 0.17 1 0.08
Holes, Ruts, Bumps 5 0.47 7 0.62 4 0.36 4 0.35 8 0.68
41
Exhibit 3- 8: Number and Percent of Fatalities by Type of Adverse Condition ( 2001- 2005)
2001 2002 2003 2004 2005
Obstruction
( protected) 2 0.19 1 0.09 1 0.09
Obstruction
( unprotected) 1 0.09 2 0.17
Obstruction
( unlighted at night) 2 0.19 4 0.35 3 0.26 6 0.51
Defective Shoulders 3 0.27
Changing Road
Width 4 0.38 4 0.36 1 0.09 4 0.34
Flooded 5 0.47 8 0.71 6 0.54 5 0.43 8 0.68
Temporary Lane
Closure 1 0.09 3 0.27 2 0.18 1 0.09 3 0.25
Wet 36 3.41 28 2.47 31 2.77 63 5.47 55 4.65
Sand, Mud, Dirt, Oil
or Gravel 8 0.76 14 1.24 10 0.89 7 0.61 4 0.34
Snow - on road 3 0.28 1 0.09 5 0.45 4 0.34
Slush 1 0.09 3 0.27 1 0.09 4 0.35 2 0.17
Ice 10 0.95 11 0.97 9 0.80 4 0.35 4 0.34
Defective Brakes 8 0.76 6 0.53 5 0.45 10 0.87 8 0.68
Defective Steering 2 0.17 2 0.17
Defective
Headlights 3 0.28 2 0.18 2 0.18 2 0.17
Defective Tail
Lights 2 0.17
Puncture or
Blowout 30 2.84 31 2.74 45 4.01 47 4.08 33 2.79
One or More
Smooth Tires 4 0.38 3 0.27 6 0.54 9 0.78 7 0.59
Defective
Windshield Wiper 1 0.08
Headlight Glare 2 0.19 4 0.35 2 0.18 3 0.26 2 0.17
Sun Glare 6 0.57 7 0.62 7 0.62 6 0.52 11 0.93
Because of Bad
Weather 5 0.45 10 0.87 3 0.25
Rain, Snow, Fog on
Windshield 4 0.38 6 0.53 5 0.45 4 0.35 1 0.08
Windshield
Obscured, Other 2 0.19 1 0.09 1 0.09
42
Again, one or more of these adverse conditions may be present at a given fatality. Exhibit 3- 9
summarizes overall data on the number of fatalities, vehicles involved, and fatalities involving
one or more adverse condition. Over the period from 2001 to 2005, the number of fatalities
ranged from 1,057 to 1,183, involving 1,447 to 1,183 vehicles. Of these incidents, 652 to 707
involved one or more adverse condition representing between 58.4 and 59.8 percent.
2001 2002 2003 2004 2005
Number of Fatalities 1,057 1,132 1,121 1,151 1,183
Number of Vehicles in all Fatal Incidents 1,447 1,496 1,516 1,532 1,621
Fatalities With One or More Adverse
Conditions 652 669 671 672 707
Percent 61.7 59.1 59.9 58.4 59.8
Fatalities With One or More Educati
Arizona State Government Publications
