Can Collision Warning Systems Mitigate Distraction Due to In-Vehicle Devices

Rear-end collisions account for approximately 28% of automotive crashes. Because driver inattention is a contributing factor in more than 60% of these collisions, rear-end collision avoidance systems (RECAS) offer a promising approach to reduce crashes and save lives. A RECAS is a device that uses electronic sensors (e.g. radar) to detect the motion of a lead vehicle, compute whether a collision is likely, and trigger an alarm to alert the driver to the impending collision. This paper presents two experiments that use a high-fidelity driving simulator to compare how well drivers can avoid crashes with and without the aid of a RECAS. The first experiment examined how variations in warning algorithm parameters affect the ability of a RECAS to aid distracted drivers in avoiding an imminent collision. The primary comparison was between algorithms that triggered an early versus late warning. Drivers were distracted with a visually demanding number reading task. The results show that an early warning helps drivers react more quickly and avoid more collisions compared to a late warning or no warning. The second experiment examined the ability of the RECAS to help non-distracted drivers avoid an imminent collision. The results show that the RECAS benefits drivers even when they are not distracted. The magnitude and type of this distraction is compared with cognitive distractions due to speech-based interactions. Potential opportunities and challenges for RECAS to mitigate the effect of in-vehicle distractions are also discussed.