Alternative means of delineating crash cushions in gore areas were investigated in laboratory evaluations. A variety of passive delineation methods, including nose panels, back panels, side treatments, and combinations of these, was evaluated. The laboratory experiments used driver's-eye-view photographic slides of road scenes, only some of which contained crash cushions. A high-resolution computer graphics and digitization system was used to convert the original photographs to computerized images, so that any desired delineation could be inserted into, or removed from, the scene. Two experiments werecarried out to investigate different aspects of the "conspicuity" of the markings. In one, viewers quickly searched a scene to determine if a crash cushion was present. Detection time, and the apparent distance of the crash cushion, were recorded. The other experiment provided only a brief fixed viewing time (1 sec), and the viewer was required to answer a series of questions about the scene; detecting crash cushions was a low priority, and crash cushions had no special relevance to the viewer. The results indicated differences between delineation and no delineation, as well as among alternative means ofdelineating, in terms of reliability of detection, speed of detection, and apparent distance of crash cushions. The findings suggest that Type 1 object markers may be less effective than other alternatives and that back panels may be an especially promising means of delineating crash cushions. There were also age-related deficits in viewers' ability to detect crash cushions.(A).
Samenvatting