This paper describes a major research project aimed at improving heavy vehicle safety through a better understanding of the way vehicle, road and driver factors interact. In 1997 New Zealand heavy vehicles were involved in 18 percent of all fatal road crashes compared to 8 percent in the US (proportional exposure rates are similar). A major difference is New Zealand's lack of an extensive divided highway network. Two-way roads typically have fatal crash rates 300 to 400 percent greater than well-constructed divided highways. Vehicle configuration also plays a role, with combination vehicles having fatal crash rates over 200 percent higher than single unit trucks on two-way roads. Driver factors are major contributors with, for example, speed being a factor in 30 percent of the crashes investigated by NZ Police CVIU. Driver simulator studies, theoretical modelling and on-road testing with instrumented vehicles are being undertaken to develop a validated model of driver-vehicle-road interaction. Specific issues being addressed include determining the extent to which drivers are aware of their vehicle's performance, road design features that may mislead drivers and hence are dangerous, truck speed advisory signs for problem curves, and how weights and dimensions may be improved to increase productivity while not compromising safety. (A)
Abstract