One thousand tractors and 2700 trailers of the US Army's line haul carrier in Germany were equipped with encapsulated lens reflective sheeting on the mudflaps. The retroreflectorization scheme was as follows: a 400 x 400 mm plate of aluminum covered with encapsulated lens, red and yellow high intensity retroreflective sheeting (hereafter called delineator plates) were mounted on all mudflaps. In addition, all trailers were marked with 4" x 96" red and yellow stripes of encapsulated lens sheeting across the rear of the trailer.
To evaluate the retroreflectorization effectiveness, a baseline of five years of nighttime rear-end collisions was established. The implementation date was February 1981, with the evaluation period to run through February 1983. Several problems in evaluation have occurred, the most significant of which are the infrequency of nighttime rear-end collisions, and the lag time before the entire fleet was marked with delineator plates.
The impetus for the retroreflectorization of the Group's vehicles was a motorcycle fatality that occurred in December 1979, where the cyclist ran into the rear of the trailer on the autobahn. Concurrently the Group was receiving 1200 new 40 foot trailers as replacements for 28 foot trailers, and there was concern about the conspicuity of these longer trailers.
The results after three years show three accidents versus the expected twelve from the baseline period. While the final results cannot be statistically validated, the favorable comments from drivers as well as the German press reinforce the face validity of increasing truck conspicuity to avoid rear-end crashes at night.