Estimation of the probability of merging at an entrance ramp of a suburban freeway and application to the road safety

Road safety intends to offer optimal safety conditions and acceptable risk levels to the road users, together with the required mobility. The first objective is to reduce the fatalities and casualties on the roads due to the vehicles. Another objective is to contain the frequency of material accidents, which induce high costs and congestion. The progress of road equipments permits to collect a large amount of data on an instrumented suburban freeway segment (site SAROT in France).Within the general framework of updating the French design guidelines for urban freeways, studies are conducted for building new models for traffic operations at on-ramps. Our research work is aimed at a better understanding of the interactions between vehicles in the merging lane and vehicles in the motorway lane, in order to improve driver behaviour and the intrinsic qualities of the road.We discuss newapproaches of merging modelling for motorway traffic.The models aim to gather general knowledge on the merging process, from the analysis of microscopic traffic data collected on the site SAROT.