Adaptive cruise control (ACC) is one system that is changing the driver-vehicle relationship. However, not all drivers are aware of the systems' capabilities or limitations. In this study, a cluster analysis was used to classify drivers based on how aware they were of the limitations associated with ACC. Three cluster groups emerged: those who are aware, unaware, and unsure of ACC limitations. Further examination revealed that drivers who were unaware or unsure exhibited potentially hazardous behavior when compared to the aware group. These two groups were more willing to use ACC when tired or on curvy roads. The unaware and unsure groups were also more likely to use conventional cruise control (CCC) in the absence of ACC. All three cluster groups reported high levels of trust in ACC. This may be problematic for the unaware and unsure groups since they may trust the system based on inappropriate expectations which can impact driver safety. Lower levels of awareness coupled with high levels of trust in ACC may correspond to potential misuse of the system. However, the findings suggest that this could be potentially mitigated through extended use of ACC.