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

Accession Number:


Record Type:



National Technical Information Service

5301 Shawnee Road
Alexandria, VA 22312 USA


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.

Report/Paper Numbers:

HS-810 594

Contract Numbers:

DTNH22-00-C-07007 Task Order 23



Corporate Authors:

Virginia Polytechnic Institute and State University, Blacksburg

Virginia Tech Transportation Institute
3500 Transportation Research Plaza
Blacksburg, VA 24061 USA

National Highway Traffic Safety Administration

Office of Human-Vehicle Performance Research, 1200 New Jersey Avenue, SE
Washington, DC 20590 USA


Klauer, S G
Dingus, T A
Neale, V L
Sudweeks, J D
Ramsey, D J



Publication Date:



Technical Report

Period Covered:

August 2004 to August 2005

Media Type:



Appendices (4) ; Figures; Photos; References; Tables

Subject Areas:

Highways; Safety and Human Factors; I83: Accidents and the Human Factor



Created Date:

Aug 3 2006 11:02AM