Abstract
Approximately one third of all accidents with cars on highways outside built-up areas happen on a wet road, both during rainfall and after it has stopped raining. During rainfall less than 10% of all vehicle-kilometres are driven, while accidents in these situations account more than 20% of all accidents. If it is accepted that in wet road conditions the proportion between the number of vehicle-kilometres and the number of accidents is approximately the same as when it is raining, it can be stated that a wet road surface is at least 2.5 times as dangerous as a dry road surface. The covering abstract for the conference is IRRD no. 216265.