The Influence of Audio Warning Urgency and Situational Urgency on Collision Avoidance Performance

Abstract

Audio warning system of collision warning system had been investigated extensively in previous studies; however, only a few of them focused on warning effectiveness under varied situational urgency. Their results suggested that warning signal should be tested under several situational urgencies to confirm its effectiveness. This leads to the objective of this study, which is to explore the effect of varied auditory warning urgency and varied situational urgency on collision avoidance performance. This paper performed an experimental evaluation for four audio warning conditions: high urgency, medium urgency, low urgency and none(no warning), with three situational urgencies: high, medium, and low situational urgency. The results indicate that varied situational urgency has some influence on the collision avoidance performance. In the aspect of brake reaction time, this study result suggests that warning with higher perceived urgency tends to improve brake reaction time in general. For brake profile, increasing the warning urgency up to the medium level improves braking behavior while high warning urgency tends to worsen it. In mean deceleration aspect, in low situational urgency, Mean deceleration tends to be decreased as the urgency of the warning increased up until the medium warning urgency, but high warning urgency increases the mean deceleration instead. Overall, medium warning urgency causes more stable and more appropriate braking response among all designed warning urgency.