September 2004 - Accident Reconstruction Newsletter

Driver Eye Glance Behavior During Car Following - April 2004

Executive Summary

A study was undertaken to characterize driver eye glance behavior during car following. Participants drove an instrumented vehicle unaccompanied on public roads that included high speed highways as well as surface streets. The drivers were paid to participate in the study and had no time pressures placed on them. The data obtained represent a baseline database of what might be termed ‘safety -ideal’ eye glance behavior during car following. Key findings are summarized below.

There is remarkable consistency in the strategy with which drivers looked away from the road ahead during car following. Simply put, they generally looked away when the range rate was effectively zero. They did not, in general, appear to take range or time headway into account to any substantial degree. This strategy appears consistent with other research on the effective stimulus for braking behavior [1, 2]. It also implies that drivers assume that the lead vehicle will not brake abruptly, a belief reinforced by common driving experience. This strategy of deciding when it is safe to look away may explain why driver inattention is a leading contributing factor to rear-end crashes: driver expectations are sometimes violated and the driver has not allotted sufficient distance (range) to recover.

Driver eye glance durations away from road ahead during car following averaged 0.6 s with a standard deviation of 0.46 s. This pattern implies that drivers during car following are more cautious about how long they will look away from the road scene ahead. Furthermore, this finding suggests that future studies of the effects of in-vehicle technology on drivers should compare in-vehicle glance durations to both glance durations in an open-road environment and in a car following setting. The results should be substantially different except for the most simple of in-vehicle tasks.

The fact that driver eye glance durations were not predicted by range, range rate, or speed perhaps reflects a combination of the demand characteristics of the activity that prompted the glance away (unknown) and a well-learned strategy drivers have to keep glance durations below about 1.6 to 2 seconds [3, 4]. The distribution of glance locations was found to reflect both individual differences among drivers with respect to age and as a function of speed regime.

DOWNLOAD THE FULL REPORT (PDF)

###

• Cell Phone – Vicarious Liability Issues
  Can You Hear Me Now?
• Drowsy Driving and Automobile Crashes
• National Survey of Distracted and Drowsy Driving - Attitudes and Behaviors: 2002
• National Survey of Speeding and Unsafe Driving - Attitudes and Behaviors: 2002
• State Distracted Driving Laws Chart
• Examination of the Distraction Effects of Wireless Phone Interfaces Using the National Advanced Driving Simulator - Preliminary Report on a Freeway Pilot Study
• Driver Eye Glance Behavior During Car Following
• Northwestern University Class Schedule

• ARC Network New Members
• October 2004 Training Events
  (Currently 15 events scheduled)
• In The News
• Membership Information

Please direct any questions regarding this issue of the Accident Reconstruction Newsletter to
the ARC Network

© 2004 ARC Network, LLC. All rights reserved.
Any comments, questions or suggestions should be e-mailed to the ARC Network.

ARC NETWORK QUICK LINKS
Homepage | Contact Us | Guest Book | Advertising
AR News | Book Store | Corporate Directory | Discussion Forum | Education | Events Calendar | Expert Witness Directory | Membership
Newsletter | Organizations | Police Department Directory | Research Directory