A. de Palma

Departure time and route choice for the morning commute

Most theoretical studies of traffic congestion during the morning commute have been limited to one origin, one destination, and one route. This paper is the first to analyze systematically user equilibrium, system optimum, and various pricing regimes for a simple network of routes in parallel. Departure time and route decisions of commuters are assumed to be governed by the tradeoff between travel time and schedule delay (the difference between actual and desired arrival time). In equilibrium without tolls wasteful queuing occurs, although the numbers of drivers on each route is the same as in the system optimum. An optimal time-varying toll eliminates queuing without affecting route usage. Uniform and step tolls alter route usage, but only slightly. Step tolls generally yield much greater efficiency gains than uniform tolls because they reduce queuing by altering departure times.

Transportation: Supply and Congestion

Transportation facilities are prone to congestion because of peaks in travel demand, inflexibility of supply, and inability to store transport services. Urban road traffic congestion and congestion in air travel impose significant economic and social costs. Traditional policies to alleviate congestion such as building new roads have had limited success at best. Congestion pricing has the greatest theoretical potential because it can affect all dimensions of travel behavior. However, congestion pricing of roads and airport runway slots has been resisted by policy makers.

The temporal use of a telephone line

Abstract This paper models the temporal use of a multi-channel telephone line. All individuals would like to complete their calls during the peak period. However, the capacity of the line is not sufficient for this. An individual therefore faces a tradeoff. If he starts telephoning during the peak period, he may have to re-dial for a long time until he gets a free line, while if he places his call during the off-peak period, his expected waiting time is reduced but the time is inconvenient (“schedule delay costs”). Equilibrium obtains when the expected costs of placing a call during the peak and off-peak periods are equalized. Various pricing policies are treated, and topics for future research are discussed. The model improves on previous work in explicitly treating the time-of-use decision and schedule delay costs. Appropriately modified, the model can be adapted to treat other telecommunication facilities.

A dynamic model of peak period traffic flows and delays in a corridor

Abstract This paper develops and analyses a dynamic model of peak period traffic flows and delays in a congested urban corridor. The model consists of a continous traffic flow model and a probabilistic travel demand model of the choice of departure time. Analytical solution is obtained for the model under no congestion and numerical simulations are used to investigate the general case with congestion. The results demonstrate the interdependencies among upstream and downstream bottlenecks and the interactions among the traffic from different origins.

Population systems with (non-)extensive interaction rates

This paper is concerned with population systems whose evolution is described by differential equations with not necessarily extensive transition rates. Some standard models in marketing, epidemiology and ecology are used to show how such systems can actually occur in concrete situations. The implications of the extensivity or not of the interaction rates are discussed and interpreted, with special emphasis on the qualitatively different behaviors induced.

Implementation of a Dynamic Traffic Simulator to the Paris Area

Juin, 2001 * THEMA-TT&R, Universite de Cergy-Pontoise, 33 boulevard du Port, 95011 Cergy-Pontoise Cedex, France. E-mail : andre.depalma@eco.u-cergy.fr. ** THEMA-TT&R, Universite de Cergy-Pontoise, 33 boulevard du Port, 95011 Cergy-Pontoise Cedex, France. E-mail : fabrice.marchal@eco.u-cergy.fr.