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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Optimization and simulation of traffic flows in the case of evacuating urban areas
TL;DR: This paper compute and simulate an evacuation plan for a neighborhood in the city of Duisburg, Germany, to demonstrate the applicability of the optimization-based simulation procedure to real-world sized problems.
Journal ArticleDOI
Centralised and decentralised signal timing optimisation approaches for network traffic control
TL;DR: This study develops and analyses the centralised and decentralised solution procedures for urban network traffic management through an optimal control framework using use of traffic flow theory, decentralised optimisation, and network decomposition techniques.
Macroscopic discontinuity modeling for multiclass multilane traffic flow operations
TL;DR: A new approach to model the (infrastructure) discontinuities of heterogeneous traffic flow operations on multilane freeways and in multilanes urban networks is established, which provides insight into the interactions of vehicles between lanes near to a bottleneck.
Journal ArticleDOI
Adaptive coordinated traffic control for stochastic demand
Lubing Li,Wei Huang,Hong Kam Lo +2 more
TL;DR: An adaptive coordinated traffic control approach in the presence of traffic demand uncertainty via the notion of Phase Clearance Reliability (PCR) is developed and a method to adjust signal offset adaptively in order to deal with stochastic demands is proposed.
Journal ArticleDOI
Multi-objective optimal predictive control of signals in urban traffic network
Xiang Li,Xiang Li,Jian-Qiao Sun +2 more
TL;DR: A novel dynamic multi-objective optimization method for designing predictive controls of network signals is proposed and is promising to improve the performance of real traffic network.
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.
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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.
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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.
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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.