A Simulation-Based Traffic Signal Control for Congested Urban Traffic Networks

Abstract

Traffic congestion in urban networks may lead to strong degradation in the utilization of the network infrastructure, which can be mitigated via suitable control strategies. This paper studies and analyzes the performance of an adaptive traffic-responsive strategy that controls the traffic light parameters in an urban network to reduce traffic congestion. A nearly optimal control formulation is adopted to avoid the curse of dimensionality occurring in the solution of the corresponding Hamilton–Jacobi–Bellman (HJB) optimal control problem. First, an (approximate) solution of the HJB is parametrized via an appropriate Lyapunov function; then, the solution is updated at each iteration in such a way to approach the nearly optimal solution, using a close-to-optimality index and information coming from the simulation model of the network (simulation-based design). Simulation results obtained using a traffic simulation model of the network Chania, Greece, an urban traffic network containing many varieties of junction staging, demonstrate the efficiency of the proposed approach, as compared with alternative traffic strategies based on a simplified linear model of the traffic network. It is shown that the proposed strategy can adapt to different traffic conditions and that low-complexity parametrizations of the optimal solution, a linear and a bimodal piecewise linear strategy, respectively, provide a satisfactory trade-off between computational complexity and network performance.

Special Issue on Recent Advances in Urban Transport and Logistics Through Optimization and Analytics

“…Two papers consider the problem of optimizing the use of traffic signals for passengers traveling in cars. Baldi et al (2019) show that traffic congestion can be mitigated via suitable control strategies. Their paper, "A Simulation-Based Traffic Signal Control for Congested Urban Traffic Networks," studies and analyzes the performance of an adaptive traffic-responsive strategy for traffic signal control.…”

Methodology Designed to Evaluate Accidents at Intersection Crossings with Respect to Forensic Purposes and Transport Sustainability

“…The term junctions controlled by light signalization means the intentional creation of time gaps of a sufficient length, so that the alternating and safe passage of vehicles is ensured from every road in the shortest time possible. A light signaling device is implemented mainly in order to enable the passage of vehicles coming from side roads and to reduce their time losses compared to the uncontrolled junctions [28]. This loss decrease should be greater than the resulting loss increase in the main direction.…”

“…The basic principle of road traffic control using a light signaling device is the time separated, alternating usage of a level junction by vehicles in the colliding traffic flows. As vehicles pass through a junction with minimum following distances, compared to the operation of a junction where the right of way is based on the system of main and slip roads, the efficiency of the junction and the safety of operation increase [28,29]. This applies only if LSD is used appropriately.…”

An adaptive design for quantized feedback control of uncertain switched linear systems

“…Such systems include multiagent systems, 1 automobile power trains, 2 traffic light controls, 3 power converters, 4 fault-tolerant systems, 5,6 and many more. Such systems include multiagent systems, 1 automobile power trains, 2 traffic light controls, 3 power converters, 4 fault-tolerant systems, 5,6 and many more.…”

“…Switched systems are used to model many systems, commonly referred to as hybrid systems, exhibiting an interaction between continuous and discrete dynamics. Such systems include multiagent systems, 1 automobile power trains, 2 traffic light controls, 3 power converters, 4 fault-tolerant systems, 5,6 and many more. In the recent decades, much effort has been increasingly devoted to studying stability and stabilization problems in switched systems.…”