The impact of attentional set and situation awareness on event detection and reaction times was investigated in 2 simulated driving experiments. Experiment 1: thirty participants viewed and reacted to thirty driving films containing unexpected items which were either driving congruent or incongruent. Group 1 completed the task without distraction; group 2 completed a concurrent conversation task. Experiment 2: thirty participants viewed and reacted to twenty driving films which contained unexpected yet driving relevant events. Half of the participants completed the task without distraction and half completed a concurrent conversation task. Measures of event detection and reaction time were recorded for both experiments. Compared to undistracted participants, dual-taskers reacted to fewer unexpected events; recorded longer reaction times; and reacted to fewer incongruent and peripheral events, suggesting an enduring attentional set for driving. Dual tasking drivers may adopt a strategy of over-reliance on schema-driven processing when attention is shared between tasks.