Relationship Between Unsignalised Intersection Geometry and Accident Rates Owen Kingsley Arndt, B.E. (Civil), M. Eng
留學生dissertation網(wǎng)This thesis is submitted as a requirement of theDoctor of Philosophy course (IF49).School of Civil Engineering,
Faculty of Built Environment and Engineering,Queensland University of Technology,March 2003.

Keywords
Intersections, Unsignalized intersections, T-intersections, Cross-roads, Accident prevention, Collision prediction, Collision avoidance, Crash avoidance, Road geometry, Road design standards.
Abstract
The aim of this research is to determine the effect of unsignalised intersectiongeometry on the rates of the various types of accidents occurring at unsignalisedintersections. A literature review has identified that there is little consistencybetween the results of previous studies. Some studies found that particularparameters had an opposite effect to what was expected. With this in mind, the
research identified reasons for these results and developed two basic approaches tomitigate some of the problems with multi-factor type studies. These approaches are‘maximise the efficiency of data collection’ and ‘develop techniques for analysingless than perfect data’. A database consisting of 206 unsignalised intersection sitesfrom throughout Queensland was used for analysis. The outcome of this researchconfirms the validity of several of the current design standards for unsignalisedintersections, in addition to identifying new engineering procedures.
Table of Contents
List of Tables ............................................................................................................................viii
List of Figures .............................................................................................................................xi
Statement of Original Authorship .............................................................................................xiii
Acknowledgements..................................................................................................................xiv
Part A
1 INTRODUCTION ...........................................................................................................1
1.1 Objectives of the Study......................................................................................................1
1.2 Background to this Research .............................................................................................2
1.3 The Roundabout Study - Arndt (1998)..............................................................................2
1.4 Potential Benefits of Undertaking Research at Unsignalised Intersections.......................4
1.5 Definitions .........................................................................................................................4
1.6 Outline of this Thesis.........................................................................................................6#p#分頁標題#e#
2 LITERATURE REVIEW ...............................................................................................9
2.1 Multi-factor Studies...........................................................................................................9
2.2 Matched Group Studies ...................................................................................................24
2.3 Before and After Studies .................................................................................................25
2.4 Traffic Conflict Studies ...................................................................................................28
2.5 Studies Relating Traffic Volumes to Accident Rates ......................................................29
2.6 Driver Behaviour .............................................................................................................31
2.7 Literature Review Summary............................................................................................38
2.8 Discussion.......................................................................................................................41
3 THESIS APPROACH...................................................................................................45
3.1 Problems with Multi-factor Studies.................................................................................45
3.2 Maximise Efficiency of Data Collection .........................................................................48
3.3 Develop Techniques for Analysing less than Perfect Data..............................................50
3.4 Discussion of the Approaches Taken in this Study .........................................................57
Part B
4 SELECTION OF UNSIGNALISED INTERSECTION SITES ................................61
4.1 Obtaining a Wide Range of Variable Values...................................................................61
4.2 Excluding Very Low Volume Intersections ....................................................................64
4.3 Types of Intersections Selected .......................................................................................65
4.4 Overview of Intersection Sample ....................................................................................75
5 ACCIDENT DATA........................................................................................................76
5.1 Source of Accident Data..................................................................................................76
5.2 Selected Analysis Periods................................................................................................77
5.3 Categorisation of the Accident Data................................................................................78
iv
6 GEOMETRIC AND OTHER VARIABLES...............................................................88#p#分頁標題#e#
6.1 Selection of Variables ......................................................................................................88
6.2 Collection of Geometric and Other Variable Data...........................................................90
6.3 Speed Prediction Model ...................................................................................................91
6.4 Vehicle Path Model..........................................................................................................95
6.5 Geometric Data Coding and Overview ............................................................................96
7 TRAFFIC FLOW DATA ............................................................................................101
7.1 Selection of Traffic Volume Variables and Collection of Data .....................................101
7.2 Conversion of Traffic Volume Data to the Same Time Period......................................101
7.3 Conversion of Calculated AADT Values to Average AADT Values............................101
7.4 Overview of Traffic Volume Data .................................................................................102
Part C
8 DATA COLLECTION SUMMARY AND PRELIMINARY ANALYSIS
PROCEDURE ..............................................................................................................105
8.1 Data Collection Summary ..............................................................................................105
8.2 Preliminary Analysis Procedure.....................................................................................105
9 ANGLE-MINOR VEHICLE ACCIDENTS..............................................................107
9.1 Vehicle Types ................................................................................................................108
9.2 Accident Severity...........................................................................................................110
9.3 Effect of Weather and Light Conditions ........................................................................111
9.4 Time of Day ...................................................................................................................113
9.5 Day of Week ..................................................................................................................113
9.6 Month of Year................................................................................................................114
9.7 Contributing Circumstance ............................................................................................115
9.8 Distribution of Data .......................................................................................................117
9.9 Geometric and Other Effects..........................................................................................118
10 ANGLE-MAJOR VEHICLE ACCIDENTS..............................................................122#p#分頁標題#e#
10.1 Vehicle Types ................................................................................................................123
10.2 Accident Severity...........................................................................................................125
10.3 Effect of Weather and Light Conditions ........................................................................125
10.4 Contributing Circumstance ............................................................................................126
10.5 Distribution of Data .......................................................................................................127
10.6 Geometric and Other Effects..........................................................................................128
11 REAR-END-MAJOR VEHICLE ACCIDENTS.......................................................131
11.1 Vehicle Types ................................................................................................................132
11.2 Accident Severity...........................................................................................................134
11.3 Effect of Weather and Light Conditions ........................................................................134
11.4 Contributing Circumstance ............................................................................................135
11.5 Geometric and Other Effects..........................................................................................136
v
12 SINGLE-THROUGH VEHICLE ACCIDENTS......................................................140
12.1 Vehicle Types ................................................................................................................142
12.2 Accident Severity ..........................................................................................................143
12.3 Effect of Weather and Light Conditions........................................................................144
12.4 Contributing Circumstance............................................................................................145
12.5 Geometric and Other Effects .........................................................................................145
13 LOW FREQUENCY INTERSECTION ACCIDENTS ...........................................148
13.1 Rear-End-Minor.............................................................................................................148
13.2 Single-Minor-Turn.........................................................................................................150
13.3 Single-Major-Turn.........................................................................................................151
13.4 Incorrect Turn ................................................................................................................153
13.5 Overtaking-Intersection .................................................................................................154#p#分頁標題#e#
13.6 Sideswipe-Major-Auxiliary ...........................................................................................156
13.7 Other Accidents .............................................................................................................156
14 LOW FREQUENCY THROUGH ACCIDENTS.....................................................157
14.1 Pedestrian......................................................................................................................157
14.2 U-Turn ...........................................................................................................................159
14.3 Changed Lanes ..............................................................................................................159
14.4 Single-Object .................................................................................................................160
14.5 Overtaking .....................................................................................................................160
14.6 Other Accidents .............................................................................................................161
15 PRELIMINARY ANALYSIS SUMMARY...............................................................162
15.1 Types and Numbers of Accidents Recorded..................................................................162
15.2 Parameters Over Represented in the Accident Data......................................................162
Part D
16 STATISTICAL MODELLING ISSUES ...................................................................165
16.1 Analysis Process ............................................................................................................165
16.2 Correlation between Parameters ....................................................................................166
16.3 Relationships between Variables and Accident Rates...................................................173
16.4 Interaction between Variables .......................................................................................178
16.5 Regression Techniques ..................................................................................................179
16.6 Acceptance and Rejection of Parameters from the Regression Analysis ......................182
16.7 Diagnostic Checks .........................................................................................................185
16.8 Validation of the Accident Models................................................................................186
17 ANGLE-MINOR VEHICLE ACCIDENTS..............................................................189
17.1 Categorisation of the Data .............................................................................................189
17.2 Variables Selected for Analysis.....................................................................................189#p#分頁標題#e#
17.3 Results of the Regression Analysis................................................................................190
17.4 Discussion of the Regression Analysis Results .............................................................196
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18 ANGLE-MAJOR VEHICLE ACCIDENTS..............................................................211
18.1 Categorisation of the Data..............................................................................................211
18.2 Variables Selected for Analysis .....................................................................................211
18.3 Discussion of the Regression Analysis Results .............................................................213
19 REAR-END-MAJOR VEHICLE ACCIDENTS.......................................................217
19.1 Categorisation of the Data..............................................................................................217
19.2 Variables Selected for Analysis .....................................................................................218
19.3 Discussion of the Regression Analysis Results .............................................................223
20 SINGLE-THROUGH VEHICLE ACCIDENTS ......................................................230
20.1 Categorisation of the Data..............................................................................................230
20.2 Variables Selected for Analysis .....................................................................................232
20.3 Discussion of the Regression Analysis Results .............................................................235
20.4 Alternative Single-Through Vehicle Accident Models..................................................238
21 LOW FREQUENCY INTERSECTION ACCIDENTS............................................242
21.1 Rear-End-Minor.............................................................................................................242
21.2 Single-Minor-Turn .........................................................................................................246
21.3 Single-Major-Turn .........................................................................................................253
21.4 Overtaking-Intersection .................................................................................................257
21.5 Remaining Intersection Accidents .................................................................................262
Part E
22 COMBINED RESULTS..............................................................................................265
22.1 Traffic Flow Variables ...................................................................................................265
22.2 Speed Parameters ...........................................................................................................267
22.3 Potential Measures to Reduce Vehicle Speed and Accident Rates ................................269#p#分頁標題#e#
22.4 Intersection Type............................................................................................................273
22.5 Relative Accident Rate of the Various Conflict Types ..................................................277
22.6 Parameters Relating to Visibility Restrictions ...............................................................280
22.7 Free Left-turn Lanes.......................................................................................................283
22.8 Warrants for the Various Major Road Turn Types ........................................................284
22.9 Variables Found Unimportant in this Study...................................................................292
22.10 Variables Yielding Unreasonable or Illogical Results ...................................................293
23 IMPLICATIONS FOR ROAD DESIGNS STANDARDS .......................................294
23.1 Intersection Design Philosophy......................................................................................294
23.2 Measures to Reduce Vehicle Speed ...............................................................................295
23.3 Intersection Type............................................................................................................295
23.4 Parameters Relating to Visibility Restrictions ...............................................................296
23.5 Warrants for Turn Types................................................................................................298
23.6 Effect of Median Width on BAR, AUR and MNR Turn Treatments ............................301
23.7 Widened Shoulder for LSR Treatments.........................................................................301
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23.8 Free Left-turn Lanes ......................................................................................................302
23.9 Line Marking .................................................................................................................302
23.10 Approach Visibility .......................................................................................................303
24 ACCIDENT COSTS AND APPLICATION OF THE RESULTS OF THIS
STUDY..........................................................................................................................304
24.1 Accident Costs...............................................................................................................304
24.2 Application of the Results of this Study ........................................................................305
25 FUTURE WORK.........................................................................................................308
25.1 Update of Road Design Standards.................................................................................308
25.2 Implications for Further Analysis of Unsignalised Intersections Using the Techniques#p#分頁標題#e#
Developed in this Study ...........................................................................................................308
25.3 Reanalyse the Data in Arndt (1998) ..............................................................................308
25.4 Combine the Results of this Study with the Updated Results of Arndt (1998) .............309
25.5 Analysis of All Forms of Roadways and Intersections..................................................309
26 CONCLUSIONS..........................................................................................................311
26.1 Results of the Literature Review ...................................................................................311
26.2 Approaches Taken in this Study ....................................................................................311
26.3 Analysis Results ............................................................................................................313
27 RECOMMENDATIONS ............................................................................................317
27.1 Implications for Road Design Standards .......................................................................317
27.2 Future Work...................................................................................................................318
Appendices
Appendix A - Accident Categories
Appendix B - Vehicle Path Model
Appendix C - Geometric Variables
Appendix D - Costs of the Various Turn Types
Appendix E - Turn Types used in this Study
Bibliography
viii
List of Tables
Table 2.1 - Speed of Minor Road Drivers Involved in Failure to Give Way
Accidents using Data from the Study Kanda and Ishida (2000) .......... 37
Table 2.2 - Summary of Results of the Various Studies Reviewed ........................... 40
Table 3.1 - Combination of Variables in Multi-factor Studies .................................. 48
Table 4.1 - Intersection Types Selected/Rejected ...................................................... 66
Table 4.2 - Location of Intersections in Analysis ...................................................... 75
Table 4.3 - Types of Intersections in Analysis........................................................... 75
Table 5.1 - Selection of Analysis Period.................................................................... 77
Table 5.2 - Two Methods of Categorising the Data used........................................... 79
Table 5.3 - Methods of Categorising the Data ........................................................... 80
Table 5.4 - Initial Accident Classification ................................................................. 81
Table 5.5 - ‘Not Included in Analysis’ Accident Category........................................ 82
Table 5.6 - Major Accident Categories ...................................................................... 85#p#分頁標題#e#
Table 6.1 - Geometric and Other Variables Identified............................................... 89
Table 6.2 - Possible Changes to Variables and .......................................................... 92
Table 6.3 - Number of Major Road Lanes ................................................................. 97
Table 6.4 - Control Type versus Number of Minor Legs........................................... 98
Table 6.5 - Median Width on Major Road versus Number of Intersection Sites..... 100
Table 7.1 - Range of Traffic Volumes Recorded on the Minor Legs ...................... 102
Table 7.2 - Range of Traffic Volumes Recorded on the Major Legs....................... 103
Table 9.1 - Types of Conflicts Recorded in the ....................................................... 108
Table 9.2 - Minor Road Vehicle Involvement Rate versus Vehicle Types.............. 110
Table 9.3 - Major Road Vehicle Involvement Rate versus Vehicle Types.............. 110
Table 9.4 - Angle-Minor Vehicle Accident Rates versus Light Conditions ............ 112
Table 9.5 - Angle-Minor Vehicle Accident Rate versus Day of Week.................... 114
Table 9.6 - Contributing Circumstances for Angle-Minor Vehicle Accidents ........ 115
Table 9.7 - Other Contributing Factors to Angle-Minor Vehicle Accidents ........... 116
Table 9.8 - Comparison of Recorded Angle-Minor Vehicle Accidents................... 117
Table 9.9 - Angle-Minor Vehicle Accident Rates for the Various Conflicts........... 120
Table 9.10 - Angle-Minor Vehicle Accident Rates.................................................. 121
Table 10.1 - Vehicle Movements - Angle-Major Vehicle Accidents ...................... 123
Table 10.2 - Turning Major Road Vehicle............................................................... 124
Table 10.3 - Oncoming Major Road Vehicle........................................................... 124
Table 10.4 - Angle - Major Vehicle Accident Rates Versus Light Conditions ....... 126
Table 10.5 - Contributing Circumstances for Angle-Major Vehicle Accidents ...... 127
Table 10.6 - Additional Contributing Factors to Angle-Major Vehicle
Accidents ............................................................................................ 127
Table 10.7 - Comparison of Recorded Angle-Major Vehicle Accidents................. 128
Table 10.8 - Angle-Major Vehicle Accident Rates for Various Conflicts............... 129
Table 11.1 - Front Vehicle Turning Movements - ................................................... 132
Table 11.2 - Rear Vehicle Involvement Rate versus Vehicle Types ....................... 133
Table 11.3 - Front Vehicle Involvement Rate versus Vehicle Types ...................... 133
Table 11.4 - Rear-End-Major Vehicle Accident Rates Versus Light Conditions.... 135
Table 11.5 - Contributing Circumstances for Rear-End-Major Vehicle
Accidents ............................................................................................ 136#p#分頁標題#e#
Table 11.6 - Rear-End-Major Accident Rates for Various Turn Treatments........... 137
Table 11.7 - Length of Right-turn Slots in Austroads (1988) and in this Study ...... 138
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Table 12.1 - Single-Through Vehicle Accidents...................................................... 141
Table 12.2 - Single-Through Vehicle Accident Rate versus Vehicle Type............. 143
Table 12.3 - Single-Through Vehicle Accident Rates Versus Light Conditions..... 145
Table 12.4 - Contributing Circumstances for Single-Through Vehicle
Accidents............................................................................................ 145
Table 12.5 - Single-Through Vehicle Accident Rates ............................................. 146
Table 12.6 - Single-Through Vehicle Accident Rates ............................................. 146
Table 13.1 - Front Vehicle Movements - ................................................................. 149
Table 13.2 - Rear-End-Minor Vehicle Accident Rates for Front Vehicle
Movements ......................................................................................... 150
Table 13.3 - Vehicle Movements -........................................................................... 150
Table 13.4 - Single-Minor-Turn Vehicle Accident Rates........................................ 151
Table 13.5 - Vehicle Movements -........................................................................... 152
Table 13.6 - Single-Major-Turn Vehicle Accident Rates ........................................ 153
Table 13.7 - Overtaking-Intersection Vehicle Accident Rates for the Various
Right-Turn Types and Line Marking Treatments (Two-Lane
Roads Only)........................................................................................ 155
Table 15.1 - Types and Numbers of Accidents Recorded in the Study ................... 163
Table 15.2 - Parameters Over Represented in the High Frequency Accident
Types .................................................................................................. 164
Table 16.1 - Combined Variables ............................................................................ 169
Table 16.2 - Secondary Variables Omitted from the Regression Analysis.............. 172
Table 17.1 - Variables and Function Types for Angle-Minor Vehicle Accidents ... 191
Table 17.2 - Results of the Regression Analysis for Angle-Minor Vehicle
Accidents............................................................................................ 192
Table 17.3 - Alternative Variables for Angle-Minor Vehicle Accidents................. 193
Table 17.4 - Regression Analysis Results for the .................................................... 195
Table 17.5 - Effect of the Variable ‘Driver Recognition of an ................................ 204
Table 18.1 - Variables and Results of the Regression Analysis .............................. 212#p#分頁標題#e#
Table 18.2 - Alternative Variables........................................................................... 213
Table 18.3 - Regression Analysis Results for the .................................................... 213
Table 19.1 - Front Vehicle Turning Movements - ................................................... 217
Table 19.2 - Variables and Results of the Regression Analysis .............................. 219
Table 19.3 - Alternative Variables for Rear-End-Major.......................................... 221
Table 19.4 - Regression Analysis Results for the .................................................... 222
Table 19.5 - Percentage of Sites in Each Category of Road Width ......................... 229
Table 20.1 - Variables and Results of the Regression Analysis .............................. 233
Table 20.2 - Regression Analysis Results for the .................................................... 235
Table 20.3 - Alternative Single-Through Vehicle Accident Models ....................... 239
Table 20.4 - Predicted Single-Through Vehicle Accident Rates for Various
Cases................................................................................................... 240
Table 21.1 - Variables and Results of the Regression Analysis .............................. 243
Table 21.2 - Regression Analysis Results for the ‘Turn’ Accident Subcategory .... 244
Table 21.3 - Variables and Results of the Regression Analysis .............................. 247
Table 21.4 - Alternative Variables for Single-Minor-Turn...................................... 248
Table 21.5 - Regression Analysis Results for the ‘Turn’ Accident Subcategory .... 250
Table 21.6 - Single-Minor-Turn Vehicle Accident Rates........................................ 251
Table 21.7 - Variables and Results of the Regression Analysis .............................. 254
Table 21.8 - Final Regression Analysis Results ...................................................... 255
Table 21.9 - Variables and Results of the Regression Analysis .............................. 258
x
Table 21.10 - Alternative Variables ......................................................................... 259
Table 21.11 - Final Regression Analysis Results for the ......................................... 259
Table 22.1 - Power Constants of the Traffic Flow Variables for the ....................... 265
Table 22.2 - Significance of the Speed Parameters for the ...................................... 267
Table 22.3 - Relative Accident Rate for 100 and 60 km/h Speeds .......................... 268
Table 22.4 - Relative Accident Rate for Four Leg Intersections versus .................. 275
Table 22.5 - Angle-Minor and Angle-Major............................................................ 277
Table 22.6 - Rates of the Various Accident Types and............................................ 279#p#分頁標題#e#
Table 22.7 - Effect of Free Left-turn Lanes on Accident Rates............................... 284
Table 24.1 - Average Cost per Accident for the Various Accident Types............... 305
xi
List of Figures
Figure 2.1 - Error of Drivers Failing to Give way at Unsignalised Intersections ...... 35
Figure 4.1 - Types of Right-Turn Treatments on Two-Lane, Two-Way Roads........ 69
Figure 4.2 - Types of Right-Turn Treatments on Multi-lane Roads .......................... 70
Figure 4.3 - Types of Left-Turn Treatments .............................................................. 71
Figure 4.4 - Subcategories of Type LSR and MNR................................................... 72
Figure 4.5 - Subcategories of Type AUR Turn Treatments Used in this Study ........ 73
Figure 4.6 - Subcategories of Type CHR Turn Treatments Used in this Study......... 74
Figure 5.1 - High Frequency Intersection and Through Accident Types .................. 86
Figure 5.2 - Low Frequency Intersection Accident Types......................................... 86
Figure 5.3 - Low Frequency Through Accident Types.............................................. 87
Figure 6.1 - 85th Percentile Car Speed versus Horizontal Curve Radius ................... 93
Figure 6.2 - Type and Number of Minor Road Approach Lanes............................... 98
Figure 6.3 - Speed Limit and Speed Environment Prior to Intersection.................... 99
Figure 6.4 - Speed Limit and Speed Environment Prior to Intersection.................... 99
Figure 9.1 - Number of Angle-Minor Vehicle Accidents........................................ 107
Figure 9.2 - Type of Vehicles versus Number of Angle-Minor Vehicle
Accidents............................................................................................ 109
Figure 9.3 - Severity of Angle-Minor Vehicle Accidents........................................ 111
Figure 9.4 - Effect of Weather and Light Conditions on Number of....................... 111
Figure 9.5 - Time of Day versus Number of Angle-Minor Vehicle Accidents ....... 113
Figure 9.6 - Month of Year versus Number of Angle-Minor Vehicle Accidents .... 114
Figure 9.7 - Types of Conflicts Recorded in the...................................................... 119
Figure 10.1 - Number of Angle-Major Vehicle Accidents Compared to the
Total Number of Accidents ................................................................ 122
Figure 10.2 - Type of Vehicle versus Number of Angle-Major Vehicle
Accidents............................................................................................ 123
Figure 10.3 - Severity of Angle-Major Vehicle Accidents...................................... 125
Figure 10.4 - Effect of Weather and Light Conditions on Number of..................... 126
Figure 10.5 - Types of Conflicts Recorded in the.................................................... 129#p#分頁標題#e#
Figure 11.1 - Number of Rear-End-Major Vehicle Accidents................................. 131
Figure 11.2 - Type of Vehicles versus Number of................................................... 132
Figure 11.3 - Severity of Rear-End-Major Accidents versus Number of
Accidents............................................................................................ 134
Figure 11.4 - Effect of Weather and Light Conditions on Number of Rear-End-
Major Vehicle Accidents (Out of the 121 Rear-End-Major vehicle
accidents, 58 were listed as unknown weather and light
conditions) .......................................................................................... 135
Figure 11.5 - Types of Conflicts Recorded in the.................................................... 136
Figure 12.1 - Number of Single-Through Vehicle Accidents.................................. 140
Figure 12.2 - Distance from Centre of Intersection Versus Number of Single-
Through Vehicle Accidents................................................................ 142
Figure 12.3 - Type of Vehicle Versus Number of ................................................... 142
Figure 12.4 - Severity of Single-Through Vehicle Accidents.................................. 143
Figure 12.5 - Effect of Weather and Light Conditions on Number of Single-
Through Vehicle Accidents (Out of the 167 Single-Through
vehicle accidents,................................................................................ 144
Figure 13.1 - Number of Low Frequency Intersection Accidents ........................... 148
xii
Figure 13.2 - Severity versus Number of Rear-End-Minor Vehicle Accidents ....... 149
Figure 13.3 - Severity versus Number of Single-Minor-Turn Vehicle Accidents ... 151
Figure 13.4 - Severity versus Number of Single-Major-Turn Vehicle Accidents ... 152
Figure 13.5 - Conflict Types Recorded in the Incorrect Turn Accident Category... 153
Figure 13.6 - Severity versus Number of Incorrect Turn Vehicle Accidents .......... 154
Figure 13.7 - Severity versus Number of Overtaking-Intersection Vehicle
Accidents ............................................................................................ 154
Figure 14.1 - Number of Low Frequency Through Accidents................................. 157
Figure 14.2 - Distance from Centre of Intersection Versus Number of
Pedestrian Accidents .......................................................................... 158
Figure 14.3 - Severity versus Number of Pedestrian Accidents .............................. 158
Figure 14.4 - Severity versus Number of Changed Lanes Vehicle Accidents......... 159
Figure 14.5 - Severity versus Number of Single-Object Vehicle Accidents ........... 160
Figure 16.1 - Relationships between Geometric and ............................................... 177
Figure 17.1 - Effect of the 85th Percentile Minor Road Approach Speed ................ 198#p#分頁標題#e#
Figure 17.2 - Effect of Sight Distance on Angle-Minor Vehicle Accidents ............ 201
Figure 17.3 - Effect of Observation Angle on Angle-Minor Vehicle Accident
Rates ................................................................................................... 202
Figure 18.1 - Effect of Sight Distance on Angle-Major Vehicle Accidents ............ 214
Figure 19.1 - Effect of Sight Distance on Rear-End-Major Vehicle Accidents....... 225
Figure 19.2 - Effect of Median Width on Rear-End-Major Vehicle........................ 226
Figure 20.1 - Effect of Vehicle Path Radius on Single-Through Vehicle
Accidents ............................................................................................ 236
Figure 20.2 - Location of Single-Through Vehicle Accidents on Horizontal
Geometric Elements in the ‘Major’ Accident Subcategory................ 238
Figure 21.1 - Effect of Minor Road Approach Speed .............................................. 251
Figure 22.1 - Effect of Sight Distance on Accident Rates ....................................... 282
Figure 22.2 - Potential Warrants for Right-Turn Treatments for an 85th
Percentile Speed of 110km/h Using the ‘By Accident Rate’
Method (estimated accident rate limited to one right-turn Rear-
End-Major vehicle accident in ten years)........................................... 286
Figure 22.3 - Potential Warrants for Right-turn Treatments for an 85th
Percentile Speed of 70km/h Using the ‘By Accident Rate’
Method (estimated accident rate limited to one right-turn Rear-
End-Major vehicle accident in ten years)........................................... 287
Figure 22.4 - Potential Warrants for Right-turn Treatments for a New
Intersection for an 85th Percentile Speed of 110km/h Using the
‘By Benefit / Cost Analysis’ Method (based on a benefit / cost
ratio of one and an design life of 20 years) ........................................ 290
Figure 22.5 - Potential Warrants for Upgrading an AUR Intersection for an 85th
Percentile Speed of 70km/h Using the ‘By Benefit / Cost
Analysis’ Method (based on a benefit / cost ratio of one and an
design life of 20 years) ....................................................................... 290
xiii
Statement of Original Authorship
“The work contained in this thesis has not been previously submitted for a degree ordiploma at any other higher education institution. To the best of my knowledge andbelief, the thesis contains no material previously published or written by anotherperson except where due reference is made”.Owen ArndtMarch 2004
xiv
Acknowledgements
The author wishes to acknowledge the assistance of the following individuals andauthorities in the preparation of this study.
The following staff from the Queensland University of Technology:#p#分頁標題#e#
• Professor Rod Troutbeck - for his continued encouragement, support andguidance throughout the duration of this thesis and for that given throughoutprevious projects.
• Mr Gareth Ridall - for his guidance and technical support
The following Queensland Department of Main Roads staff and offices:
• Mr Arthur Hall - for his support of this work
• Mr Jon Douglas - for his support of this work
• Mr Mark Logan - for supply of accident data
• Traffic Engineering and Road Use Management Division - for the supply of
http://www.ttc-switch.com/dissertation_writing/traffic data
• Various engineers, designers and traffic personnel from within the following Main
Roads district offices for the supply of information: