Recent research suggests that advanced driver assistance systems (ADAS) technologies, such as forward collision warning (FCW), have the potential to reduce rear-end and other forward collisions. The primary objective of this literature review is to provide a summary of relevant research on how the presence of FCWs may or may not impact driver perception response time (PRT) to forward hazards. Our review of the literature identified several primary variables that impact driver PRT including warning modality, inattention/distraction, and expectancy. These variables, their implications, and future research are discussed.