Driver Visibility in Adverse Weather - Expert Report (Redacted) Expert Article

For this predawn two-vehicle crash, involving a loader crossing the road and a SUV on the through road, the crash site was reported to have been dark with no streetlights. Eyewitnesses variously described crash-scene weather as some combination of mist, fog, or very light rain.

Dr. Lee was tasked with determining:

  • How did these weather and lighting conditions affect visibility of the striking driver to a crossing loader?
  • What was the visibility of the vehicle operator crossing the road?

Ray Lee’s analysis included: an extrapolation of visibility and weather conditions reported at a nearby National Weather Service station to the crash site; the position of the sun; the visibility attributes of both vehicles, such as the SUV’s headlights, reflectors and the side of the loader itself; how the visibility to these elements was attenuated by the weather; and, a theoretical contrast determination and comparison to the threshold contrast required for detection, taking in to account the driver’s expectancy.

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Featured Expert

Raymond L. Lee, Meteorologist & Visibility Expert

Raymond L. Lee, Ph.D.

Meteorologist & Visibility Expert
Dr. Lee is an expert in determining weather conditions at a particular time and location, how weather and ambient conditions affect human vision, and how weather events affect other incidents such as… read more.