Are Novelty Effects of Road Safety Treatments Observable in Simulator Experiments

Time and experimental design constraints can mean that driving simulator studies present “one-off” events, scenarios or treatments. In the real world, however, drivers will typically encounter the same road layout time and time again. Even when drivers do take unfamiliar routes, road safety interventions (e.g. speed humps) conform to legislation and are thus relatively predictable for drivers. Studies that evaluate a diverse range of road safety interventions with comparable metrics are rare, and even rarer, are those which attempt to evaluate persistence effects by exposing drivers to multiple instances of the treatments. This paper reports on the durability of the effects of six top-performing speed-reducing treatments on driver behaviour in a (8 DoF) driving simulator. Participants encountered all the treatments four times, with corresponding baseline sections. The results indicate that some treatments are more effective over time than others; additionally the pattern of effects differed, with some treatments demonstrating their strongest effect when they were unfamiliar to the driver, whilst others were more successful as familiarity increased.