EFFECTIVENESS OF HEAVY TRUCK CONSPICUITY TREATMENTS UNDER DIFFERENT WEATHER CONDITIONS

The United States has had enhanced conspicuity standards for heavy trucks in place for over three years. The standards which were developed by the National Highway Traffic Safety Administration (NHTSA) dictate the use of retro-reflective tape as a means to primarily improve nighttime conspicuity. Effective January, 1997, Transport Canada has amended Canadian Motor Vehicle Safety Standard (CMVSS) #108 to adopt reciprocal standards. While both the Canadian and U.S. standards were based on the results of previous studies, little consideration was given to the effectiveness of different treatment patterns or colours under varying weather conditions. The University of New Brunswick has undertaken a series of truck conspicuity tests under different weather conditions including clear, rain, snow, and fog. The effectiveness of nine different conspicuity treatments for the rear of the trailer, and five for the side, were evaluated. A complete outline of solid white retro-reflective tape was found to be the most effective configuration to increase the threshold of visibility for the rear of the trailer under all weather conditions. The NHTSA configuration ranked no higher than fourth among the rear scenarios evaluated. A continuous stripe of white retro-reflective tape was found to be the most effective configuration to increase the threshold of visibility of the side of the trailer under three of the four weather conditions. The NHTSA configuration ranked the lowest of all side configurations considered under each weather condition.