Quieter vehicles result in riskier street-crossing decisions

Using high-fidelity acoustic simulations of approaching vehicles, we investigated whether the vehicle source intensity affects pedestrians’ street-crossing decisions and introduced a novel measure of the riskiness of crossing decisions. Analyses of psychometric functions indicated that participants accepted shorter gaps and made riskier crossing decisions when the vehicle source intensity was lower compared to higher. This effect of source intensity occurred in both an auditory-only and an audio-visual condition, though it was stronger when only auditory information was available. Analyses of the trial-by-trial data showed that the vehicle sound intensity at the moment of the crossing decision was the most important predictor of the decisions in the auditory-only condition. In the audio-visual condition, sound intensity also was significantly associated with the crossing decision, but visual cues dominated. Implications for road traffic safety are discussed, specifically in relation to interactions between pedestrians and electric vehicles.