This report discusses a literature study and the results of 48 simulated collisions with a more or less vertical wall at four different gradients, namely 2 degrees, 6 degrees, 11 degrees and 17 degrees. The combined study investigates how the profile of a concrete vehicle barrier may be optimised. The results of the literature and simulation study concur well with each other. They show that the gradient of the more or less vertical wall can be maximally 10 degrees in relation to the rolling movement of the vehicles. The application of a 5 cm wide step (extension) to the foot of the wall has no deleterious consequences. When the step width is increased to 10 cm, this produces some increase in the angle of roll, but not to such an extent that it causes the car to overturn. Therefore, the application of a step to the foot of the wall can be regarded as a potentially useful modification of the nearly vertical barrier.
Abstract