Jorge A. Laval

Learn More
It is postulated that lane-changing vehicles create voids in traffic streams, and that these voids reduce flow. This mechanism is described with a model that tracks lane changers precisely, as particles endowed with realistic mechanical properties. The model has four easy-to-measure parameters and reproduces without re-calibration two bottleneck phenomena(More)
This paper introduces a parsimonious theory for congested freeway traffic that describes the spontaneous appearance of oscillations and their ensuing transformation into stop-and-go waves. Based upon the analysis of detailed vehicle-trajectory data, we conclude that timid and aggressive driver behaviours are the cause for this transformation. We find that(More)
In this paper, congestion dynamics along crowded freeway corridors are modeled as a conservation law with a source term that is continuous in space. The source term represents the net inflow from ramps, postulated here as a location-dependent function of the demand for entering and exiting the corridor. Demands are assumed time-independent, which is(More)
This paper introduces a multi-lane hybrid theory that treats lane-changing as temporary blockages, because this is what is physically observed in reality. For maximum accuracy lanechanging vehicles are modeled as discrete particles endowed with limited acceleration capabilities that interact realistically with the multi-lane continuum stream. This(More)
This paper shows that a wide range of stochastic extensions of the kinematic wave model tend to the same parameter-free expression for the probability of congestion at a given time-space point. This is shown for white noise initial density with deterministic and stochastic fundamental diagram in the case of Riemann problems and the bottleneck problem. It is(More)
This report is part of PATH Task Order 4141 and shows how moving obstructions can be modeled numerically with kinematic wave theory. It shows that if a moving obstruction is replaced by a sequence of fixed obstructions at nearby locations with the same “capacity”, then the error in vehicle number converges uniformly to zero as the maximum separation between(More)
This paper studies the system optimum dynamic traffic assignment in a network consisting of a surface street grid and a congested freeway section. Vehicles can be diverted through off-ramps and on-ramps can be metered. The family of solutions are identified graphically using Newell’s queueing diagrams. Because enforcing diversion is still a technological(More)
This paper analyzes the dynamic traffic assignment problem on a two-alternative network with one alternative subject to a dynamic pricing that responds to real-time arrivals in a system optimal way. Analytical expressions for the assignment, revenue and total delay in each alternative are derived as a function of the pricing strategy. It is found that(More)
  • 1