A driver's reaction time to a visual or audible signal has often been put forward as a possible indicator of when a driver is becoming too `fatigued' to drive safely. A practical implementation of such an approach would be to monitor a driver's level of fatigue periodically during a journey by means of a `secondary reaction time task'. The primary task would of course be driving. The secondary task would be one which required the driver to respond as quickly as possible by pressing a switch (using hand or foot) when a light flashed or a buzzer sounded. The time taken by the driver to respond to such a signal (or the average time over a number of `observations') would be taken as the measure of the driver's level of fatigue. As the driver becomes more fatigued, so - it is claimed - his or her reaction time (RT) would increase, and this slowing of response could be used to issue a warning to the driver of the need to take a break. This paper reviews the literature relevant to such a driver fatigue monitor in an attempt to assess whether reaction time could be expected to be effective and reliable indicator of tiredness. (A)
Samenvatting