Analysis of the effects of adaptive cruise control on driver behavior and awareness using a driving simulator

Adaptive cruise control (ACC) systems assist drivers by automatically adjusting vehicle speed with respect to the driver selected time-gap to the lead vehicle and maximum desired speed. Although ACC systems have been around for 20 years, drivers are not always fully aware of their limitations. The main focus of this research was to investigate the limitations of the ACC system and the resulting effects on driver performance, taking into account variations of mental workload. Thirty participants drove two simulated scenarios, with and without the ACC system active, in a fixed-base driving simulator. The variability of the observed parameters between the drives with and without the ACC provided insights into individual driver performance, impact of age and gender, and behavioral trends resulting from changes to mental workload. Data on cognitive workload were measured using a detection response task (DRT) device to monitor availability of mental resources during the various tasks. The statistical analysis showed that with an active ACC system, participants reached lower maximum speeds, maintained longer headways, and reacted slower and more abruptly to sudden events. The data from the DRT showed a significantly lower cognitive load when participants were subject to secondary tasks during the ACC scenarios.