Technical Report Documentation Page

1. Report No.

DOT HS 810 594

2. Government Accession No.

3. Recipient’s Catalog No.

4. Title and Subtitle

The Impact of Driver Inattention on Near-Crash/Crash Risk: An Analysis Using the 100-Car Naturalistic Driving Study Data

5. Report Date

April 2006

6. Performing Organization Code

7. Author(s)
Klauer, S.G., Dingus, T. A., Neale, V. L., Sudweeks, J.D., and Ramsey, D.J.

8. Performing Organization Report No.

9. Performing Organization Name and Address

Virginia Tech Transportation Institute
3500 Transportation Research Plaza (0536)
Blacksburg, Virginia 24061

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

DTNH22-00-C-07007 Task Order 23

12. Sponsoring Agency Name and Address

National Highway Traffic Safety Administration
NVS-331, Room 6220
Office of Human-Vehicle Performance Research
400 Seventh Street SW., Room 6220
Washington, DC 20590

13. Type of Report and Period Covered

Technical Report
August 2004 to August 2005

14. Sponsoring Agency Code


15. Supplementary Notes

Michael Perel, Julie Barker, and Michael Goodman served as contracting officer’s technical representatives for this work.

16. Abstract

The purpose of this report was to conduct in-depth analyses of driver inattention using the driving data collected in the 100-Car Naturalistic Driving Study. An additional database of baseline epochs was reduced from the raw data and used in conjunction with the crash and near-crash data identified as part of the original 100-Car Study to account for exposure and establish near-crash/crash risk. The analyses presented in this report are able to establish direct relationships between driving behavior and crash and near-crash involvement. Risk was calculated (odds ratios) using both crash and near-crash data as well as normal baseline driving data for various sources of inattention. The corresponding population attributable risk percentages were also calculated to estimate the percentage of crashes and near-crashes occurring in the population resulting from inattention. Additional analyses involved: driver willingness to engage in distracting tasks or driving while drowsy; analyses with survey and test battery responses; and the impact of driver’s eyes being off of the forward roadway.

The results indicated that driving while drowsy results in a four- to six-times higher near-crash/crash risk relative to alert drivers. Drivers engaging in visually and/or manually complex tasks have a three-times higher near-crash/crash risk than drivers who are attentive. There are specific environmental conditions in which engaging in secondary tasks or driving while drowsy is more dangerous, including intersections, wet roadways, and areas of high traffic density. Short, brief glances away from the forward roadway for the purpose of scanning the driving environment are safe and actually decrease near-crash/crash risk. Even in the cases of secondary task engagement, if the task is simple and requires a single short glance the risk is elevated only slightly, if at all. However, glances totaling more than 2 seconds for any purpose increase near-crash/crash risk by at least two times that of normal, baseline driving.

17. Key Words

100-Car, Naturalistic, Intelligent Vehicle Initiative, Driver Behavior, Human Factors, Inattention, Distraction, Eyes Off Forward Roadway, Driver Drowsiness

18. Distribution Statement

  This report is available from the National Technical Information Service, Springfield, Virginia 22161, (703-605-6000), and is free of charge from the NHTSA Web site at www.nhtsa.dot.gov

19. Security Classif. (Of this report)

20. Security Classif. (Of this page)

21. No. of Pages


22. Price

Form DOT F 1700.7 (8-72)                             Reproduction of completed page authorized