Dynamic traffic control: decentralized and coordinated methods

ALLONS-D is a decentralized real-time traffic control scheme. Through simulations, the scheme is shown to be suitable for adaptive control of an isolated intersection. An efficient tree searching algorithm, constrained only by a maximum and minimum green time per phase, is used to find a traffic signal plan that minimizes delay. Differences between ALLONS-D and other real-time traffic control schemes, such as OPAC, are described. The scheme can also be used to reduce travel times on transit routes. For arterial networks of intersections, ALLONS-D is capable of inducing a level of coordination that results in progressive signal plans. An extension of the scheme to provide network-wide optimization of traffic signals is explained in the form of a two-layer scheme. Simulation experiments are performed with a newly developed simulator called STNS.