The purpose of this examination was to investigate whether reducing the standard taper length noted in Design Standard #613, Duration Note 2 increases accident likelihood. In addition to taper length, the presence of a visually occluding lead vehicle was considered as a key-moderating factor that might influence work zone safety. Taken together, Taper Length and Lead Vehicle formed the two primary factors under consideration for Experiment 1. A second experiment replicated the experimental conditions of the first Experiment, with the major difference that additional vehicles were included in the simulation. Generally speaking, results suggest that the proposed reduced taper work zone configuration increases the accident likelihood, and that this likelihood is augmented when a lead vehicle occludes work zone entry. Examining the vehicle-to-cone area, which represents the distance from the participant's vehicle to the primary and secondary channelizing cones demarcating work zone entry, largely supports these conclusions. In addition to vehicle occlusion, such factors as day/night driving, weather, alternative work zone lengths, traffic density, personality, and driver experience should also be considered as moderating factors for work zone design. Modern competitors for driver attention should also be considered in the context of work zone design. New devices such as cell phones, navigational devices, and the like, may alter how urban work zones are planned and configured. The authors strongly suggest that future work in this area continue. (Author/publisher)
Abstract