Reducing Accidents Involving Driver Fatigue

328 Pages·2009·2.81 MB·English

STATE OF CALIFORNIA DEPARTMENT OF TRANSPORTATION
TECHNICAL REPORT DOCUMENTATION PAGE
TR0003 (REV. 10/98)
1. REPORT NUMBER 2. GOVERNMENT ASSOCIATION NUMBER 3. RECIPIENT’S CATALOG NUMBER

CA 09/1092
4. TITLE AND SUBTITLE 5. REPORT DATE

Rest Areas – Reducing Accidents Involving Driver Fatigue May 11, 2009
6. PERFORMING ORGANIZATION CODE

7. AUTHOR(S) 8. PERFORMING ORGANIZATION REPORT NO.
Ipsita Banerjee, Joon ho Lee, Kitae Jang, Swati Pande, David
Ragland UCB-ITS-PRR-2010-15
9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. WORK UNIT NUMBER
University of California, Berkeley
Traffic Safety Center
2614 Dwight Way #7374 11. CONTRACT OR GRANT NUMBER

Berkeley, CA 94720-7374 65A0208-6220

12. SPONSORING AGENCY AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED
California Department of Transportation
Division of Research and Innovation, MS-83 Final
1227 O Street 14. SPONSORING AGENCY CODE

Sacramento CA 95814
15. SUPPLEMENTAL NOTES

16. ABSTRACT

Rest areas are a countermeasure for fatigue; what role do they play in fatigue-related freeway collisions? The
present study spatially evaluates fatigue collisions.
In California, of 2,203,789 highway collisions recorded between 1995 and 2005, fatigue collisions accounted for
1.3% (‘strict’ definition of fatigue) and 9.7% (‘expanded’ definition). Collisions in the vicinity of rest areas were
investigated using two different approaches:
1. 10-miles up/downstream of rest areas
2. Distance traveled from rest areas
Sample t-tests indicated that both fatigue and non-fatigue collisions decreased statistically significantly
downstream of rest areas. Collisions due to fatigue tended to decrease immediately downstream of rest
areas, then climbed after about 30 miles from rest areas, while non-fatigue collisions remained the same.
Binomial tests confirmed that the percentage of fatigue collisions further than 30 miles from rest areas was
significantly higher.
The study also compared ramps at rest areas to other ramps and found that trucks were the primary vehicle type
involved in rest area ramp collisions. ‘Parked, parking’ movements caused the highest number of collisions on
ramps at rest areas, compared with ‘proceeding straight’ movements for other ramps. The comparison revealed
that some rest areas had too few parking spots.
Finally, the study explored the growth of informal rest areas: shoulders frequented by truck drivers when
other safe stopping opportunities do not exist. The study analyzed collision rates at informal rest area ramps
and determined that the rates were higher, on average, than at other ramps. Analysis of fatigue related
collisions adjacent to informal rest areas provided mixed results regarding the efficacy of informal rest areas
in reducing highway collisions. However, higher incidence of fatigue-related collisions at these locations
supports the need for additional rest areas.

17. KEY WORDS 18. DISTRIBUTION STATEMENT
driver fatigue, rest area, srra, safety roadside rest area, truck safety, No restrictions. This document is available to the
vehicle safety, accident rate, fatigue collision, highway safety, public through the National Technical Information
shoulder parking
Service, Springfield, VA 22161
19. SECURITY CLASSIFICATION (of this report) 20. NUMBER OF PAGES 21. PRICE

Unclassified 328
Reproduction of completed page authorized
For individuals with sensory disabilities, this document is available in Braille, large print,
audiocassette, or compact disk. To obtain a copy of this document in one of these
alternate formats, please contact:
Division of Research and Innovation, MS-83,
California Department of Transportation, P.O. Box 942873,
Sacramento, CA 94273-0001.
CALIFORNIA PATH PROGRAM
INSTITUTE OF TRANSPORTATION STUDIES
UNIVERSITY OF CALIFORNIA, BERKELEY
Rest Areas – Reducing Accidents
Involving Driver Fatigue
Ipsita Banerjee, Joon ho Lee, Kitae Jang,
Swati Pande, David Ragland
California PATH Research Report
UCB-ITS-PRR-2010-15
This work was performed as part of the California PATH Program of the
University of California, in cooperation with the State of California Business,
Transportation, and Housing Agency, Department of Transportation, and the
United States Department of Transportation, Federal Highway Administration.
The contents of this 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 State of California. This
report does not constitute a standard, specification, or regulation.
Final Report for Task Order 6220
April 2010
ISSN 1055-1425
Report Number CA 09/1092 Expenditure Authorization 65680633 36220
CALIFORNIA PARTNERS FOR ADVANCED TRANSIT AND HIGHWAYS
DISCLAIMER STATEMENT

This document is disseminated in the interest of information exchange. The contents of
this report reflect the views of the authors who are responsible for the facts and
accuracy of the data presented herein. The contents do not necessarily reflect the
official views or policies of the State of California or the Federal Highway Administration.
This publication does not constitute a standard, specification or regulation. This report
does not constitute an endorsement by the Department of any product described herein.

For individuals with sensory disabilities, this document is available in Braille, large print,
audiocassette, or compact disk. To obtain a copy of this document in one of these
alternate formats, please contact: the Division of Research and Innovation, MS-83,
California Department of Transportation, P.O. Box 942873, Sacramento, CA 94273-
0001.
UC Berkeley Traffic Safety Center

Rest Areas
Reducing Accidents Involving Driver Fatigue

Prepared for the California Department of Transportation,
Contract 65A0208, Task Order 6220

Ipsita Banerjee, Joon ho Lee, Kitae Jang,
Swati Pande, David Ragland

May 11, 2009
Rest Areas, Reducing Accidents Involving Driver Fatigue

The mission of the UC Berkeley Traffic Safety Center is to reduce traffic fatalities
and injuries through multi-disciplinary collaboration in education, research and
outreach. Our aim is to strengthen the capability of state, county, and local
governments, academic institutions and local community organizations to enhance
traffic safety through research, curriculum and material development, outreach and
training for professionals and students.

Traffic Safety Center
2614 Dwight Way #7374
Berkeley, CA 94720-7374
Telephone: [phone]
Fax: [phone]
Rest Areas, Reducing Accidents Involving Driver Fatigue

May 11, 2009

Rest Areas
Reducing Accidents Involving Driver Fatigue

PREPARED BY

Ipsita Banerjee
Joon Ho Lee
Kitae Jang
Swati Pande
David R. Ragland

University of California Traffic Safety Center (TSC)
Under sponsorship from Caltrans and California PATH
Rest Areas, Reducing Accidents Involving Driver Fatigue

ACKNOWLEDGEMENTS

We extend our sincere thanks to the many people who made significant
contributions to this project.

We want to thank the California Department of Transportation (Caltrans) for
funding this study. Special thanks are due to Gloria Gwynne from the Division of
Research and Innovation, and Lori Butler and Doug Brown from the Landscape
Architecture Program.

We would like to thank Rebecca May for editing the document.

The contents of this 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 STATE OF CALIFORNIA.
This report does not constitute a standard, specification, or regulation.
Reducing Accidents Involving Driver Fatigue

TABLE OF CONTENTS
TABLE OF CONTENTS .................................................................................................. I 
FIGURES .......................................................................................................................... II 
TABLES ........................................................................................................................... III 
1.  EXECUTIVE SUMMARY ........................................................................................ 4 
2.  INTRODUCTION....................................................................................................... 6 
3.  LITERATURE REVIEW .......................................................................................... 7 
3.1  Introduction ............................................................................................................ 7 
3.2  Characteristics and Magnitude of Fatigue-Related Collisions ............................... 7 
3.3  Effect of Fatigue on Performance .......................................................................... 8 
3.4  Causes of Fatigue ................................................................................................... 9 
3.5  Countermeasures .................................................................................................... 9 
3.6  Effect of Rest Areas on Fatigue & Necessary Rest Area Characteristics ............ 11 
4.  DEFINITIONS OF FATIGUE COLLISIONS ...................................................... 14 
4.1  Strict Definition Fatigue Collisions ..................................................................... 14 
4.2  Expanded Definition Fatigue Collisions .............................................................. 14 
5.  STATEWIDE FATIGUE-COLLISION ANALYSIS ............................................ 16 
6.  SPATIAL ANALYSIS — WITHIN ±10 MILES OF REST AREAS ................... 21 
6.1  Methodology ........................................................................................................ 21 
6.2  Results for I-5 ...................................................................................................... 21 
7.  SPATIAL ANALYSIS — COLLISIONS AS A FUNCTION OF DISTANCE
FROM REST AREAS .............................................................................................. 27 
7.1  Methodology ........................................................................................................ 27 
7.2  Analysis of Aggregated Collision Data ............................................................... 29 
8.  REST AREA CLOSURES ....................................................................................... 36 
9.  FATIGUE RAMP ANALYSIS ................................................................................ 37 
10. INFORMAL TRUCK STOPS ................................................................................. 39 
10.1 Ramp Collisions .................................................................................................. 39 
10.2 Fatigue-Related Highway Collisions at Informal Rest Areas ............................ 41 
10.3 Summary of Findings .......................................................................................... 41 
11. DISCUSSION ............................................................................................................ 43 
APPENDIX 1: LITERATURE REVIEW .................................................................... 45 
A1.1  Annotated Bibliography: Characteristics and Magnitude of Fatigue Related
Crashes 46 
A1.2  Annotated Bibliography: Effect of Fatigue on Performance ........................ 92 
A1.3  Annotated Bibliography: Causes of Fatigue ................................................. 99 
A1.4  Annotated Bibliography: Countermeasures ................................................ 118 
A1.5  Annotated Bibliography: Effect of Rest Stop Availability on Fatigue ....... 149 
APPENDIX 2: STATE-WIDE FATIGUE-COLLISION TABLES ......................... 203 
Trends in Collisions Statistics ................................................................................... 203 
APPENDIX 3: SPATIAL ANALYSIS – WITHIN ±10 MILES OF REST STOPS 227 
A3.1  I-5 Northbound............................................................................................ 228 
A3.2  I-5 Southbound............................................................................................ 244 
APPENDIX 4: SPATIAL ANALYSIS – COLLISIONS AS A FUNCTION OF
DISTANCE FROM REST STOPS........................................................................ 261 
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Rest Areas, Reducing Accidents Involving Driver Fatigue

A4.1  I-5 Northbound............................................................................................ 261 
A4.2  I-5 Southbound............................................................................................ 268 
A4.3  I-8 Eastbound .............................................................................................. 275 
A4.4  I-8 Westbound ............................................................................................. 277 
A4.5  I-10 Eastbound ............................................................................................ 279 
A4.6  I-10 Westbound ........................................................................................... 281 
A4.7  CA-101 Northbound ................................................................................... 283 
A4.8  CA-101 Southbound ................................................................................... 286 
APPENDIX 5: FATIGUE RAMP ANALYSIS .......................................................... 289 
A5.1  Intersection/Ramp Accident Location (IRL) .............................................. 289 
A5.2  Comparative Analysis ................................................................................. 292 
A5.3  Vehicle Type ............................................................................................... 292 
A5.4  Vehicle Type Excluding IRL=4 .................................................................. 293 
A5.5  Primary Collision Factor ............................................................................. 293 
A5.6  Primary Collision Factor Excluding IRL=4 ................................................ 294 
A5.7  Type of Collision ........................................................................................ 295 
A5.8  Type of Collision Excluding IRL=4 ........................................................... 295 
A5.9  Movement ................................................................................................... 296 
A5.10  Movement Excluding IRL=4 ...................................................................... 296 
A5.11 Conclusions .................................................................................................... 297 
APPENDIX 6:  INFORMAL TRUCK STOPS ..................................................... 298 
A6.1 Ramp Collisions ............................................................................................... 298 
A6.2 FATIGUE RELATED COLLISIONS AT INFORMAL REST AREAS,
DESIGNATED REST AREAS ................................................................................ 303 
A6.2.1 FATIGUE RELATED COLLISIONS AT INFORMAL REST AREAS,
DESIGNATED REST AREAS AND TRUCK SCALES ........................................ 307 
FIGURES
Figure 1. Trends in Collision Statistics, Overall and Fatigue-Related ............................. 16 
Figure 2. Strict Definition of Fatigue: Aggregated Collision Results of 23 Rest Areas
Over 11 Years ................................................................................................................... 22 
Figure 3. Expanded Definition of Fatigue: Aggregated Collision Results of 23 Rest
Areas Over 11 Years ......................................................................................................... 23 
Figure 4. Percentage of Aggregated Strict and Expanded Definition Fatigue Collisions,
Northbound ....................................................................................................................... 23 
Figure 5. Cumulative Collision Counts Due to Fatigue and Non-Fatigue Factors ........... 27 
Figure 6. Comparison of Cumulative Collision Counts (Step 3) ...................................... 28 
Figure 7. Oblique Cumulative Collision Counts (Step 4) ................................................. 28 
Figure 8. Discount Factors for Cumulative Collision Counts ........................................... 30 
Figure 9. Oblique Cumulative Collision Counts Based on the Strict Definition .............. 30 
Figure 10. Oblique Cumulative Collision Counts Based on the Expanded Definition .... 31 
Figure 11. Percentage of Collisions, Strict Definition of Fatigue ..................................... 34 
Figure 12. Percentage of Collisions, Expanded Definition of Fatigue: 34 Rest Areas,
11 Years Data .................................................................................................................... 34 
Figure 13. Ramp Location Code (IRL) From TASAS Data ............................................. 37 
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