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Summer and winter time: what are the effects on road safety?    Sep 24, 2018

Summer and winter time: what are the effects on road safety?
Sep 24, 2018


Prof. dr. Tom BRIJS



The possible abolition of summer and winter time raises a lot of questions. Do we need to convert to a permanent summer time or rather stay with winter time? And what is the effect on our biological clock? In the newspaper De Morgen, some scientist discuss these matters. Prof. Tom Brijs is one of them. He discusses the relation between summer and winter time, sleep deprivation and road safety.

When he only looks at accident rates, Tom Brijs, professor Transportation Sciences at Hasselt University, cannot tell how often and to what extent fatigue due to sleep deprivation plays a role. “Nobody will admit that he or she was fatigued after an accident. However, we suspect that fatigue is an important factor in one fifth of the accidents – we infer this from the number of run off the road – accidents, where there are no breaking tracks, and the accidents in which drivers run-in at the tail of the traffic jam.”

Driving simulator experiments, learned Prof. Brijs in June that people meander more on the road and drive slower after a short night of sleep. They are also less course stable and use their rear-view mirror less.

The most recent study about the impact of summer time on road safety from February this year from New Zealand revealed that on the first day after the switch from winter to summer time, the number of accidents increases with 16 percent, and on the second day with 12 percent.

“But the summer time lasts seven months,” noticed Tom Brijs. “You could also argue that there are less accidents during summer time because it stays longer light at night and that therefore the accidents in the first days after the start of the summer time are compensated. There is no convincing statistical evidence to prove that the number of accidents is higher in summer time.”


Read the full article in De Morgen of Saturday, September 22 or online (Dutch).