Effects of Auditory Alerts for Vehicle-to-Vehicle (V2V) Collision Warning Systems

Abstract

Collision warning systems (CWSs) have shown great benefits in improving traffic safety by alerting drivers of potential collisions. However, some warning systems require information from nearby vehicles, which could be addressed uniquely by vehicle-to-vehicle (V2V) communications. Different alerting cues are needed given the type of threat, whether they can be obviously identified (lead vehicle slowing down) or more hidden in nature (intersection conflicts). However, a unified standard for designing and implementing the warning alert for these systems still does not exist. The goal of this dissertation is to examine the effectiveness of auditory collision warnings and identify their impacts on drivers’ avoidance performance. Two driving simulator studies with different V2V scenarios were conducted. The objective of the first study was to examine the effects of acoustic forward collision warnings (FCWs) on drivers’ avoidance behavior in a rear-end collision scenario (with an apparent threat). The findings showed that driving behavior, i.e. reaction time and response intensity differed given FCWs with different urgency levels. The objective of the second study was to identify the effects of intersection movement assist (IMA) warning messages on drivers’ avoidance behavior in a red-light-running (RLR) scenario (with a latent threat). The findings showed that drivers’ avoidance performance and eye movements were significantly impacted by the presented warning information and training of the system. Combined data from two studies, partial least squares (PLS) path models were developed to reveal the causal relationships among warning conditions, drivers’ avoidance behavior, and collision abatement. The models illustrated that the auditory warnings have both a direct and indirect effect on collision occurrence with the indirect effect playing a more critical role. Understanding the effects of warnings will help target the appropriate auditory characteristics and warning contents for different CWSs.