Beeping ADAS: reflexive effect on drivers’ behavior

Advanced driver assistance systems (ADAS) are designed to assist individuals while they are at the wheel of a motor vehicle. Many ADAS emit acoustic signals when parameters such as drivers’ maintained speed exceed given thresholds. This study examines the early and late effects on lane keeping and speed maintenance produced by both the onset of and prolonged exposure to a continuous beep like those emitted by ADAS. While driving a simulator along a straight road section, participants were presented with a single, continuous beep and its effect on drivers’ behavior was investigated. The findings show that the abrupt onset of beeping startles drivers, causing them to take their foot off the accelerator and, momentarily, deviate from the correct trajectory within the lane. This behavior is to be considered particularly dangerous, since ADAS are designed to beep when driving conditions become critical, i.e., precisely when drivers should not be distracted and should concentrate on the driving task. In response to this disturbance, drivers are observed to execute corrective behavior, i.e., braking, in order to regain control of their vehicle. These results support the idea that the abrupt onset of an acoustic stimulus like those emitted by ADAS can potentially disrupt driving. Researchers and car manufacturers should therefore consider this aspect of in-car technology interactions when designing new ADAS.