Risking the road: how drivers perceive risk
We have long assumed that drivers’ perceptions of risk play an important role in guiding their on-road behaviour. The goal of this research was to examine how accurately drivers perceive risk while driving. To do this, we compared drivers’ continuous perceptions of risk to an independent measure of the risk associated with those roads (using road protection scores from the KiwiRAP database). High-definition videos of rural roads, filmed from the drivers’ perspective, were presented to 69 participants seated in a driving simulator while they indicated the momentary level of risk they were experiencing by moving a risk meter mounted on the steering wheel. Results showed that drivers’ perceptions of risk were generally in agreement with the objective risk, but that certain road situations were perceived as being riskier than the objective risk, and perhaps more importantly, the risk of other situations was significantly under-rated. Horizontal curves and narrow lanes were associated with over-rated risk estimates, while intersections and roadside hazards such as narrow road shoulders, power poles and ditches were significantly under-rated. Analysis of eye movements indicated that drivers did not fixate these under-rated objects. An analysis of the road design elements at 77 locations in the video revealed five road characteristics that predicted nearly 80% of the variance in drivers’ risk perceptions; horizontal curvature, lane and shoulder width, gradient, and the presence of median barriers. The identification of situations with under-and over-rated risks has clear implications for rural highway design.