Abstract
Road traffic models on networks have been extensively studied in recent years. However, the conditions to be applied at junctions are still poorly understood. The aim of this paper is to describe some transitions from discrete models, in which individual vehicle dynamics are detailed, to continuous models, expressed in terms of scalar conservation laws or Hamilton-Jacobi equations, thus justifying some junction conditions. This work is in collaboration with N. Forcadel and Régis Monneau.