If the idea of an obstacle is broadly interpreted, every object which is the way of a vehicle is an obstacle. According to this definition all road users are also obstacles. In this literature study only exclusive fixed objects along the highway, such as lighting columns, traffic signs, trees, telephone poles and columns for fly overs will be considered. All these have a useful function, but can produce danger for the road users by their position and design. It is established that the presence of obstacles on road shoulders increases the number and severity of collisions with obstacles. Possibilities for solutions are discussed for (1) making the necessary obstacles more safe by means of break-away and base slip-joint constructions and (2) protecting the other obstacles by so called obstacle safety devices.
Abstract