Safe driving depends on how much the driver is able to create an internal representation of the relevant parts of the traffic environment. It is propagated that a series of mental concepts is successively activated during driving. Once a concept is activated, reactions to similar objects are facilitated (priming effect). In order to investigate to which extent activated concepts influence the behaviour while driving, a driving simulatorstudy was performed. A traffic scene was constructed which was presented under three conditions. In two conditions living vs. static objects were presented in order to activate corresponding mental concepts (prime stimuli). After a short period of time an event emerged sharing attributes of the same mental concept (target). In the control condition no related stimulus was shown previously. 23 subjects took part in the experiment each assigned to one of the experimental conditions. Response latencies and braking behaviour data to appearing events were collected. In order to check which stimuli were inspected, eye-movements were recorded via a SMI eye-tracker. The results showed that subjects responded faster to emerging events if corresponding concepts were activated previously. Thus, mental activities during driving can be understood as a response to a sequence of activated concepts triggered by salient stimuli of the traffic scene.