Urban Transportation Networks: Equilibrium Analysis With Mathematical Programming Methods

Highway Capacity Manual改訂の動向--テイラ-教授の講演より

Traffic congestion in urban road and freeway networks leads to a strong degradation of the network infrastructure and accordingly reduced throughput, which can be countered via suitable control measures and strategies. After illustrating the main reasons for infrastructure deterioration due to traffic congestion, a comprehensive overview of proposed and implemented control strategies is provided for three areas: urban road networks, freeway networks, and route guidance. Selected application results, obtained from either simulation studies or field implementations, are briefly outlined to illustrate the impact of various control actions and strategies. The paper concludes with a brief discussion of future needs in this important technical area.

/pdf/review-of-road-traffic-control-strategies-2pzcx3izzi.pdf

Review of road traffic control strategies

Network Optimization: Continuous and Discrete Models

Where's the Learning in Service-Learning?

Optimization Policies for Adaptive Control (OPAC) is a computational strategy for real-time demand-responsive traffic signal control. It has the following features: (a) It provides performance results that approach the theoretical optimum, (b) it requires on-line data that can be readily obtained from upstream link detectors, (c) it is suitable for implementation on existing microprocessors, and (d) it forms a building block for demand-responsive decentralized control in a network. Studies undertaken in the development of this strategy and the testing of its performance via the NETSIM simulation model are described.

Opac: a demand-responsive strategy for traffic signal control

Progression schemes are widely used for traffic signal control in arterial streets. Under such a scheme a continuous green band of uniform width is provided in each direction along the artery at the desired speed of travel. A basic limitation of existing bandwidth-based programs is that they do not consider the actual traffic volumes and flow capacities on each link in their optimization criterion. Consequently they cannot guarantee the most suitable progression scheme for different traffic flow patterns. In this paper we present a new optimization approach for arterial progression that incorporates a systematic traffic-dependent criterion. The method generates a variable bandwidth progression in which each directional road section can obtain an individually weighted bandwidth (hence, the term multi-band). Mixed-integer linear programming is used for the optimization. Simulation results indicate that this method can produce considerable gains in performance when compared with traditional progression methods. It also lends itself to a natural extension for the optimization of grid networks.

https://ocw.nctu.edu.tw/course/tco001/B8.pdf

A multi-band approach to arterial traffic signal optimization

Setting traffic signals in a signal-controlled street network involves the determination of cycle time, splits of green time, and offsets. Part I of this paper considers the network coordination problem, i.e., given a common cycle lime and green splits at each intersection, determine offsets for all signals. Part II considers the more general synchronization problem, i.e., determine simultaneously all the control variables for the network including offsets, splits, and cycle time. In Part I, a link performance function is developed to express the loss incurred by platoons traveling through a signal-controlled intersection us a function of link offset. Integer variables enter the formulation because of the periodicity of the traffic lights: The algebraic sum of the offsets around any closed loop of the network must equal an integral number of cycle limes. The optimization problem is formulated as a mixed-integer linear program and a test network is solved by branch-and-bound techniques using IBM's MPSX pac...

Optimization of Traffic Signal Settings by Mixed-Integer Linear Programming

The Real-time Traffic Adaptive Control System (RT-TRACS) represents a new, state-of-the-art system in advanced traffic signal control. It has been developed cooperatively by a team of U.S. academic, private and public researchers under the guidance of the Federal Highway Administration (FHWA). The system provides a framework to run multiple traffic control algorithms, existing ones as well as new adaptive algorithms. The OPAC (Optimized Policies for Adaptive Control) control strategy, which provides a dual capability of distributed individual intersection control as well as coordinated control of intersections in a network, is the first adaptive algorithm implemented within the RT-TRACS framework. OPAC was the first comprehensive strategy to be developed in the U.S. for real-time traffic-adaptive control of signal systems. This paper presents the operational features of the OPAC algorithm and describes the implementation and-field testing of OPAC within the RT-TRACS system.

Nathan H. Gartner

Papers

Opac: a demand-responsive strategy for traffic signal control

A multi-band approach to arterial traffic signal optimization

Optimization of Traffic Signal Settings by Mixed-Integer Linear Programming

Implementation of the OPAC adaptive control strategy in a traffic signal network

Arterial-based control of traffic flow in urban grid networks