Objectives, Stimulus and Feedback in Signal Control of Road Traffic

This paper identifies the prospective role of a range of intelligent transport systems technologies for the signal control of road traffic. We discuss signal control within the context of traffic management and control in urban road networks, and then present a controltheoretic formulation for it that distinguishes the various roles of detector data, objectives of optimisation, and control feedback. By reference to this, we discuss the importance of different kinds of variability in traffic flows, and review the state of knowledge in respect of control in the presence of different combinations of them. In light of this formulation and review, we identify a range of important possibilities for contributions to traffic management and control through traffic measurement and detection technology, and contemporary flexible optimisation techniques that use various kinds of automated learning.