How drivers judge the safety of the road
The 'objective' crash risk of a road section can be estimated using either historical crash data or using crash risk relationships based on road features and operating conditions. Understanding the ‘perceived’ crash risk of a road section is more difficult as it’s based on how drivers judge the safety of the road. Perceived risk is important as drivers behaviour is linked to how safe they think a specific section of road is. Road safety can be compromised when the perceived risk is a lot lower than the objective crash risk. Drivers need clear messages of where the road is safe and where it’s less safe, so they drive more carefully in less safe situations. This research compares the perceived risk specified by surveyed drivers for various road sections with the objective risk, as calculated using the KiwiRAP crash risk rating method. Drivers rated perceived risk using three different surveys methods; an online web-survey of over 500 drivers rating the risk of various sites from photos; a sample of drivers rated video files and photos of road sections in Waikato and Canterbury, New Zealand; and participants drove a route in Canterbury and rated the risk and likely safe speed of road sections. Participants also ranked benefits of potential counter-measures. Results showed drivers rated curves and narrow road sections with a high perceived risk, while roadside hazards typically had a lower risk.