There are just about 40 foggy days in Belgium in an average year but they result in 160 persons dying or sustaining injuries on the country’s roads every 12 months, the Vias road safety institute indicated in a press release on Saturday.
The press release was issued on the 25th anniversary of Belgium’s worst-ever road tragedy, a massive pile-up involving over 200 vehicles on the E-17 between Ghent and Kortrijk in which 10 people died, 56 sustained severe injuries and 30 were slightly injured.
Paradoxically, the average severity of accidents occurring under foggy conditions is twice as high as that of average accidents. The average death rate for accidents is 18 per 1,000, but for fog-related mishaps it is 34 per 1,000. This occurs even though people are expected to drive more slowly under foggy conditions, which should, theoretically, reduce the severity of accidents, the institute pointed out. It also noted that 80% of accidents linked to fog occur between October and March.
Vias attributes the higher casualty rates during foggy days to two main phenomena: overestimation of distances and the vacuum-cleaner effect.
Fog causes distances to appear, on average, 50% greater than they really are, the institute stresses. If motorists are driving, for example, a little less than 10 metres behind the car in front, they feel they are 20 metres away. This explains why drivers often fail to keep at a safe distance from the preceding vehicle on foggy days, the institute explained.
The vacuum-cleaner effect occurs because drivers tend to stay close to the car in front to avoid losing their way and to be able to see its lights. When a motorist sees a car approaching from behind, (s)he tends to accelerate to avoid being slammed from the rear, so instead of slowing down, the speed of traffic increases, Vias explained.