Abstract
From available data it cannot be concluded that driving over a long period causes a decrease in driving performance. There are some differences in driving performance during the whole day, but these count also during short trips. In the morning the risks are probably greater and after lunch there is an extra risk. In the evening performance may be at its best, but not later on, because lack of sleep then plays a part. Starting for a long holiday trip after a working day and then driving the whole night is really dangerous. The small amount of traffic at night increases the danger, due to the lack of stimulation which decreases the activity level.