Perceived risk, speed and countermeasures

A large number of factors (including road design, traffic volume, complexity) have been shown to influence the risk that drivers feel in any given situation. Previously we have shown that curves, hills, road width and median barriers were the road features that best predicted drivers’ perceptions of risk. The present study examined the relationship between drivers’ perceptions of risk and the speed they choose to drive. High definition video footage of a series of rural road sections was presented to participants whilst they were seated in the driving simulator. During the first part of the task, participants were asked to adjust the speed of the car to whatever they would choose if they were driving their own car. After this, participants were shown the same clips again (either at the speed they chose or at the speed the footage was recorded) and were asked to provide a continuous rating of how safe or unsafe they felt. Analyses revealed that higher speeds were associated with lower levels of perceived risk. In general, scenarios with high traffic volumes were driven at lower speeds and rated as higher risk compared to low traffic scenarios. Interestingly though, neither speed or risk ratings changed as a result of high traffic volume on roads with a wire rope median barrier. The presence of a police car led to the greatest reduction in speed. These findings provide insights into the relationship between risk and speed and the effectiveness of a range of countermeasures.