This report is the third in a series of four human factors experiments to examine the effects of cooperative adaptive cruise control (CACC) on driver performance in a variety of situations. The experiment reported here was conducted in a driving simulator scenario in which the subject driver was embedded in a platoon of CACC-equipped vehicles. The experiment explored the interaction effect of the presence or absence of an auditory warning with the presence or absence of automated braking on drivers’ responses to a maximum deceleration crash avoidance event. The subject was in the fourth position in a five-car platoon. Dependent measures were crash avoidance (yes/no), manual brake reaction time (seconds), and adjusted time to collision (seconds). The results indicated that a crash avoidance safety benefit was achieved with full CACC (warning and automated braking) but not otherwise. Brake reaction times were longer when automated braking was present, but without the auditory alarm, about half the drivers took too long to react. (Author/publisher)
Abstract