Extremum-seeking for adaptation of urban traffic signal control

This paper investigates the application of an extremum-seeking scheme to fine-tune the parameters of a "local" urban traffic signal control strategy to improve its performance. A set of conditions that the local traffic controller has to satisfy for stability of the closed-loop system are introduced. Employing a self-organised traffic light scheme as the local controller, it is shown that this strategy satisfies the aforementioned conditions, and its optimality is dependent on the selection of a certain parameter. It is then demonstrated that, by employing an ES scheme, it is possible to always regulate this parameter close to its optimum given any traffic conditions.