Are trees along the road bad for road safety?


Over a quarter of (registered) road deaths in the Netherlands are due to run-off-road crashes (see the question How often do run-off-road crashes occur?). It can be deduced from crash registration BRON that half of the run-off-road crashes involve a crash with a tree. Trees within the clear zone are therefore considered road safety hazards.

A recurrent misconception is that trees close to the road reduce speed and could therefore benefit road safety [31]. However, crash research on roads with a speed limit of 80 km/h and higher (in the Netherlands and abroad) shows that obstacles close to the road, including trees, increase the risk of a serious crash by about a factor of one and a half to two [20]. This implies that (unshielded) trees within the clear zone, regardless of a possible limited restraining effect on driven speeds, significantly increase the risk of a serious run-off-road crash.

Part of fact sheet

Safe roadsides

Every year, about 140 fatal 'run-off-road crashes' involving motor vehicles (excluding two-wheelers) are registered in the Netherlands: they result Meer

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