Conference Proceeding

Familiarity and Distraction Affect Drivers’ Responses to In-Vehicle Warnings for a Hazard that is Not Yet Visible

  • James W Jenness (Westat, Rockville, MD)
  • Donald L Benedick (Westat, Rockville, MD)
  • Richard W Huey (Westat, Rockville, MD)


On-road experiments measured drivers’ initial responses to in-vehicle emergency electronic brake light (EEBL) warnings indicating hard braking by some vehicle in the lane ahead. Participants drove within a platoon of four research vehicles on an Interstate highway with other traffic present. Speed and time gap between the participant’s vehicle and the vehicle immediately ahead were measured before and after a warning was triggered. This paper examines the effects of prior training about EEBL warnings and driver distraction on responses to the warning when the hazard (braking vehicle in lane ahead) was blocked from view by an intervening vehicle. An EEBL warning, if effective, should encourage drivers to immediately reduce their speed and increase the time gap between their vehicle and the vehicle ahead. We hypothesized that the warning would be more effective for drivers who had received training about the meaning of EEBL warnings as compared to naïve drivers; and more effective for visually distracted drivers as compared to drivers who were looking ahead but saw no hazard when the warning was triggered. Results suggest that speed reductions following onset of the warning were increased by training and decreased by distraction. The EEBL warning elicited the most robust response from drivers who were not distracted and from those had been trained about the warning system. There was no evidence for an interaction between these two factors. These results suggest that training drivers about vehicle safety systems may increase proper behavioral responses, thereby increasing the effectiveness of in-vehicle warnings.

How to Cite:

Jenness, J. & Benedick, D. & Huey, R., (2017) “Familiarity and Distraction Affect Drivers’ Responses to In-Vehicle Warnings for a Hazard that is Not Yet Visible”, Driving Assessment Conference 9(2017), 396-402. doi:

Rights: Copyright © 2017 the author(s)

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Published on
29 Jun 2017
Peer Reviewed