Numerous accidents occur on roundabouts without being taken into account in safety studies, due to the fact that the risk of fatal injuries in this situation is relatively low. This type of accident represented only 1% of injuries in 2001. However, they generate damage to the road and create disruptions for drivers by causing traffic jams. For this reason, research work has been undertaken by the LCPC (the French Central Laboratory for Roads and Bridges) and the Laboratoire Régional de Lyon (Regional Laboratory of Lyon) in order to highlight the link between infrastructure characteristics and HGV accidents. Part of this work focused on the parameters influencing accidents occurring on roundabouts and was divided into three steps. Firstly, a literature review was made, in order to identify several roundabouts where accidents occur. This work was done with the CETE Normandie Centre (a technical service of the French Ministry of Transport, which is specialised in road safety). The whole study selected three roundabouts for simulations. This article presents the results obtained with one of the three. Secondly, a software called PROSPER was used, which allows the simulation of vehicle and road interactions. This software was first validated by a study on Heavy Truck Rollover Simulations (Delanne et al., 2002). Specific dynamic tests were carried out with an instrumented truck and PROSPER was proved to give accurate predictions of vehicle dynamics parameters such as yaw speed or wheel lift. Lastly, geometrical parameters (crossfall) and surface characteristics (Sideway Force Coefficient) were modified in order to evaluate their influence on road accidents. The study particularly focused on the maximum longitudinal speed, the lateral acceleration, the maximum roll speed and the roll angle of the vehicle.
Heavy Goods Vehicles accidents on roundabouts: parameters of influence