The paper presents results of research on driver reactions in accident situations. The tests were conducted on Kielce Racing Track and in driving simulator autoPW within the scope of the N509 016 31/1251 research project. One hundred drivers in the test sample were subjected to a simulated hazard situation during which an obstacle (a passenger car) entered the road area while a cargo truck occupying the opposite lane limited the space for performing an avoidance manoeuvre. Specially designed, safe car mock-ups were used for the track tests as the obstacles. This paper shows and analyses the results of measured values used to describe the driver’s reaction to such risks: driver reaction time and the probability of specific defensive manoeuvres being performed by the driver. These parameters were shown as a function of risk time.