Relevant road risk evaluation is required to build safe road and to adopt adequate maintenance strategy. One of the most crucial point for this evaluation is to determine the limits of control for given vehicles on a studied road. These limits have to be known for ensuring safe range of using conditions and acceptable safety margins. They are usually estimated by expertise methods which are lacking of physical basis. The proposed algorithm (termed EWA for "Earth Worm Algorithm") aims to establish these physical limits for a given combination of the system vehicle/infrastructure/driver. Based on an iterative genetic algorithm, it manages to take into account a large set of driver behaviour, vehicle handling and road properties. Numerical convergence has been tested for various cases and a validation has been achieved. In perspectives, extended experimental validation campaigns and comparison with analytical criteria should strengthened the "Earth Worm Algorithm".
