Conference Proceeding

Perception of Approaching Motorcycles by Distracted Drivers May Depend on Auxiliary Lighting Treatments: A Field Experiment

  • James Jenness (Westat, Rockville, MD)
  • Richard Huey (Westat, Rockville, MD)
  • Shawn McCloskey (Westat, Rockville, MD)
  • Jeremiah Singer (Westat, Rockville, MD)
  • Jeremy Walrath (Westat, Rockville, MD)
  • Elisha Lubar (Westat, Rockville, MD)
  • Neil Lerner (Westat, Rockville, MD)


A field experiment was conducted in daylight with 32 participants to determine whether left turning drivers’ gap acceptance in front of approaching motorcycles depends on the motorcycle’s forward lighting treatment. Five experimental lighting treatments including a modulated high beam headlamp, or the low beam headlamp plus pairs of low-mounted auxiliary lamps, high-mounted auxiliary lamps, both high- and low-mounted auxiliary lamps, or low-mounted LED lamps were compared to a baseline treatment with only the low beam headlamp illuminated. Participants viewed the approaching traffic stream (including the motorcycle) on an active roadway and indicated when it would be safe (and not safe) to initiate a left turn across the opposing lanes. Participants also shared their attention with a secondary visual distraction task that took their eyes off the forward roadway. Participants did not know that the purpose of the study was to measure their responses to approaching motorcycles. Based on participants’ indications of the last safe moment to turn, the mean temporal safety margin provided to the approaching motorcycle did not differ significantly between any of the experimental lighting treatments and the baseline treatment. However, having either low-mounted auxiliary lamps or modulated high beam lamps on the motorcycle significantly reduced the probability of obtaining a potentially unsafe short safety margin as compared to the baseline lighting treatment. Overall, the results suggest that enhancing the frontal conspicuity of motorcycles with lighting treatments beyond an illuminated low beam headlamp may be an effective countermeasure for daytime crashes involving right-of-way violations.

How to Cite:

Jenness, J. & Huey, R. & McCloskey, S. & Singer, J. & Walrath, J. & Lubar, E. & Lerner, N., (2011) “Perception of Approaching Motorcycles by Distracted Drivers May Depend on Auxiliary Lighting Treatments: A Field Experiment”, Driving Assessment Conference 6(2011), 525-531. doi:

Rights: Copyright © 2011 the author(s)

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Published on
30 Jun 2011
Peer Reviewed