Abstract
This report summarizes a series of studies designed to investigate fundamental human factors issues associated with the implementation of adaptive cruise control (ACC) systems. Recommendations from studies conducted under test track and open highway conditions indicate the following: 1) headway settings in a range of 1.0 to 2.0 seconds may be adequate for a majority of drivers, 2) an acceleration level of 1.0 to 1.5 mph/s was preferred in lane change scenarios, and 3) a deceleration level less than 0.1 g was preferred when transitioning from a cruise to a follow state behind a slower lead vehicle.