Abstract
In this report a method is described to determine the risk caused by vehicles that leave the road and thereafter collide with a roadside safety barrier. The method uses an event tree to model the consequences of three possible outcomes of an accident: No breakthrough of the safety barrier, breakthrough of the safety barrier but no successive accient and breakthrough of the safety barrier with a successive accident. The nature of a successive accident depends on the function that has to be protected, for example the opposite road, a railway or buildings. (A)