When most of the driving tasks are performed automatically, a driver's level of alertness may decline, as has been pointed out in the study of the phenomenon called `highway hypnosis'. One possible countermeasure is to periodically vary the speed (Wertheim 1978), but the authors have not found any studies that directly assess the effectiveness of this countermeasure. The objective of our study has been to provide empirical evidence regarding the effects of this strategy on the level of driver activation on a motorway route in real traffic. In the present study activation level as indexed by a relative measure based on slow EEG activity tended to be significantly higher when speed was modified periodically than when it remained constant. In addition, this index tended to be progressively higher when the speed was constant during the first part of the route, while the same thing did not occur when the speed was modified periodically. Finally, no significant differences between the constant and varying speed conditions were obtained with respect to any of the cardiovascular indices related to the effort put into driving and the stress experienced in the situation. (Author/publisher)
Samenvatting