Driver Choice of Headway with Auditory Warnings

Two major causes of rear-end collisions are driver distraction and the tendency for some drivers to maintain insufficient headways with other vehicles. Previous research into in-vehicle collision avoidance systems has focused on warning drivers in near-collision situations with short headways (e.g., less than 1 second). The current study focused on mid-range headways and on warning distracted drivers to maintain safe following distances. Subjects performed a simulated car-following task in which the lead vehicle periodically decelerated. The lead vehicle was otherwise programmed to maintain a minimum following distance of 2 seconds—although the subjects could drive more slowly to leave a longer headway. On trips with an auditory headway warning, the subjects tended to leave larger headways, particularly on trips in which they performed a secondary task as well.