There are more than 200 countries in the world and roughly ten of them have an independent safety board or transport safety board. These boards conduct investigations into single accidents in the aviation, shipping, rail and road transport sectors and sometimes pipelines. This paper will concentrate on two aspects of accident investigations as conducted by transport safety boards: depth and independence. The position defended here is as follows: independent and in-depth investigations of single accidents as conducted by the transport safety boards also generate added value in the case of road traffic.