The aim of the study was to analyse the effects of driving speed on subsidiary auditory reaction time performance in long-term car driving on a motorway with a speed limit of 110 km/h. Driving distance was about 200 km. Comparisons were made between 70 km/h, 90 km/h and 110 km/h. It was found that reaction time performance was slightly inferior at the lowest speed compared to the highest speed. Effects on mood and alertness were also studied. It was found that the drivers rated themselves as less "energic" towards the end of the journey when driving at the slowest speed compared to the fastest speed. No similar effects were demonstrated for the other two factors studied (stress, alertness). When asked to rank the different speed conditions with respect to experienced sleepiness/tiredness, it was found that the drivers ranked the slowest speed as more sleepiness/tiredness provoking compared to the fastest speed. No after-effects were demonstrated for the three factors studied. After-effects on "simple" reaction time performance were also studied. No effects of speed level were found for this measure. (A)
Abstract