The purpose of this program was to define a range of minimally acceptable large truck conspicuity enhancements that could be used as a basis for revised Federal regulations. The report begins with a review of the literature in the area of truck visibility and includes an analysis of truck crash statistics intended to show the magnitude of the problem and suggest how upgraded markings might prove beneficial. The investigation considered upgrading marking systems on large trailers by use of retroreflective materials. A number of laboratory and field studies were carried out. These assessed the value of using a pattern in the marking material, the form the pattern should take, the placements of the treatment on the trailer, the effect of retroreflective markings on the detection and identification of stop and turn signals, and the trade-off between the width and retroreflective intensity of the treatment material. In addition, field surveys were conducted to assess the effect of environmental dirt on the performance of the marking systems and the durability of retroreflective materials when used on trucks. (A)
Samenvatting