Driver performance and situation awareness are affected by critical human factors, such as the driver's interaction with alerting schemes, and the distractions that he or she faces while driving. We conducted an experiment to study the efficacy of a single master alert versus multiple individual alerts for different Advanced Driver Assistance Systems (ADAS), and how they affect a driver's response to imminent collision situations while distracted. The ADAS warning systems included auditory alerts for imminent frontal collisions, or unintentional left/right lane departures. Regarding the master alarm versus individual alarms, our results showed that there was a significant difference in drivers' reaction times under Forward Collision Warning (FCW) conditions, but that there was no significant difference under Lane Departure Warning (LDW) conditions.