Traffic Operations at an Entrance Ramp of an Urban Freeway : First results

Within the general framework of updating the French design guidelines for urban freeways, some studies are conducted for building of a new model for traffic operations at on-ramps. One of them, described is this paper, aims to gather general knowledge on the merging process, from the analysis of microscopic traffic data collected on an instrumented urban freeway section. This equipment delivers vehicle trajectories, sampled at a 50 m interval. In a first step, empirical evidence on lane use and operating speeds has been established, and risk indicators at merging locations have been computed. Then, vehicles interactions have been studied, so as to model the merging probability as a function of the traffic environment. On-going works and perspectives are presented to conclude.