Journal ArticleDOI
The cell transmission model, part ii: network traffic
TLDR
This article shows how the evolution of multi-commodity traffic flows over complex networks can be predicted over time, based on a simple macroscopic computer representation of traffic flow that is consistent with the kinematic wave theory under all traffic conditions.Abstract:
This article shows how the evolution of multi-commodity traffic flows over complex networks can be predicted over time, based on a simple macroscopic computer representation of traffic flow that is consistent with the kinematic wave theory under all traffic conditions. The method does not use ad hoc procedures to treat special situations. After a brief review of the basic model for one link, the article describes how three-legged junctions can be modeled. It then introduces a numerical procedure for networks, assuming that a time-varying origin-destination (O-D) table is given and that the proportion of turns at every junction is known. These assumptions are reasonable for numerical analysis of disaster evacuation plans. The results are then extended to the case where, instead of the turning proportions, the best routes to each destination from every junction are known at all times. For technical reasons explained in the text, the procedure is more complicated in this case, requiring more computer memory and more time for execution. The effort is estimated to be about an order of magnitude greater than for the static traffic assignment problem on a network of the same size. The procedure is ideally suited for parallel computing. It is hoped that the results in the article will lead to more realistic models of freeway flow, disaster evacuations and dynamic traffic assignment for the evening commute.read more
Citations
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Dynamic Origin-Destination Demand Flow Estimation Under Congested Traffic Conditions: A General Framework
TL;DR: In this paper, a path-flow based optimization model is developed to minimize the deviation between observed and estimated traffic states and the deviations between aggregated path flows and target OD flows, subject to dynamic user equilibrium constraints represented by a gap-function-based reformulation.
Journal ArticleDOI
Reliable evacuation planning via demand inflation and supply deflation
ManWo Ng,S. Travis Waller +1 more
TL;DR: In this paper, an evacuation route planning model that both accounts for demand uncertainty (i.e. the number of evacuees) as well as capacity uncertainty was proposed to ensure reliability.
Book ChapterDOI
Self-Organized Control of Irregular or Perturbed Network Traffic
TL;DR: A fluid-dynamic model for the simulation of urban traffic networks with road sections of different lengths and capacities is presented, allowing one to efficiently simulate the transitions between free and congested traffic, taking into account congestion-responsive traffic assignment and adaptive traffic control.
Journal ArticleDOI
A Two-level Traffic Light Control Strategy for Preventing Incident-Based Urban Traffic Congestion
TL;DR: This work designs a two-level strategy at signalized intersections for preventing incident-based urban traffic congestion by adopting additional traffic warning lights and uses timed Petri nets to describe the cooperation between traffic lights and warning lights.
Journal ArticleDOI
Bidirectional pedestrian fundamental diagram
Gunnar Flötteröd,Gregor Lämmel +1 more
TL;DR: In this article, a bidirectional fundamental diagram (FD) is derived that defines direction-specific flow rates as functions of direction specific densities and guarantees that the instantaneous density changes that would result from these flows stay bounded between zero and jam density.
References
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Journal ArticleDOI
Shock Waves on the Highway
TL;DR: In this article, a simple theory of traffic flow is developed by replacing individual vehicles with a continuous fluid density and applying an empirical relation between speed and density, which is a simple graph-shearing process for following the development of traffic waves.
Journal ArticleDOI
Nonlinear Effects in the Dynamics of Car Following
TL;DR: In this paper, it was shown that a small amplitude disturbance propagates through a series of cars in the manner described by linear theories, except that the dependence of the wave velocity on the car velocity causes an accleration wave to spread as it propagates and a deceleration wave forming a stable shock.
Journal ArticleDOI
A simplified theory of kinematic waves in highway traffic, part I: General theory
TL;DR: In this paper, it is shown how a formal solution for A ( x, t ) can be evaluated directly from boundary or initial conditions without evaluation at intermediate times and positions, and the correct solution, which is the lower envelope of all such formal solutions, will automatically have discontinuities in slope describing the passage of a shock.
Journal ArticleDOI
A simplified theory of kinematic waves in highway traffic, part II: Queueing at freeway bottlenecks
TL;DR: In this article, the authors proposed a method to relate the cumulative flow curve at any junction to the net cumulative entrance flow at this junction, and the cumulative curve for the freeway at the next upstream junction and/or the next downstream junction.