How to explain the large reduction of accidents in which unprotected road users were involved after the introduction of daytime running lights DRL ? : a hypothesis related to road user behaviour.

Daytime running lights were introduced in Finland and Sweden in the 70s. It was found that daylight accidents involving more than one vehicle were reduced by 10% while daylight accidents between motor vehicles and unprotected road users were reduced by 15-20%. This was unexpected since it had been feared that greater visibility of vehicles to each other might make unprotected road users less visible. Although the detection distance of a dark object, when driving at night on low beam, is 50 m and stopping distance about 100 m, vehicles drive at 90-100 kph because obstacles on the road are so rare that drivers feel in full control. Drivers are taught to regard children in traffic as unreliable. It is found however that drivers do not reduce speed when children at present, but that the `unreliable' children take evasive action to keep out of the way of the `reliable' drivers. Since unprotected road users cannot rely for their safety on drivers, they must ensure that they keep out of the way of vehicles. Daytime running lights make this much easier. For comments on this paper, see C 6536.