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:
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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