As the amber light is quite small, it may be mistaken for a roadside reflector, the type used on mailboxes, utility poles and as driveway delineators. Although it can be seen, the motorist does not perceive it as a hazard until it is too later. Since I wrote the 1988 article, I have become involved with the reconstruction of numerous other types of underride cases where conspicuity is a problem. Certainly, we have all been called to accidents where someone runs into the rear of a semitrailer on the open highway. Part of the problem is driver expectation.
Car drivers expect that.
If, however, a semi has pulled directly onto the roadway from the emergency lane or for some reason is traveling, only 30 MPH, a motorist may see the taillights and clearance lights but gains on the truck faster than expected. By the time the driver realizes the truck is going much slower than normal, he or she may be too close to avoid it. The ease by which an object can be perceived. Since the emergency strip is clearly that, a stopping place for emergencies, a driver unfamiliar with the road may perceive the truck ahead to be merely going down the road in the driving lane. Too often, car drivers don't see trucks until too late.