A traffic-flow model with constraint for the modeling of traffic jams



Abstract:

Recently,  Berthelin, Degond, Delitala and Rascle introduced a traffic flow model describing the formation and the dynamics of traffic jams. This model which consists of a Constrained Pressureless Gas Dynamics system assumes that the maximal density constraint is independent of the velocity. However, in practice, the distribution of vehicles on a highway depends on their velocity. In this paper we propose a more realistic model namely the Second Order Model with Constraint (SOMC model), derived from the Aw & Rascle model, which takes into account this feature. Moreover, when the maximal density constraint is saturated, the SOMC model ``relaxes'' to the Lighthill & Whitham model. We prove an existence result of weak solutions for this model by means of cluster dynamics in order to construct a sequence of approximations and we solve completely the associated Riemann problem.
 

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