Metro Traffic Regulation from the Passenger Perspective

Maintaining metro ridership in the future will require an increasing focus on customer perceptions of the service quality. This work outlines a process whereby passenger expectations may be encapsulated into a mathematical evaluation function that can then be used in an on-line optimization procedure. The function proposed penalizes excess waiting time, travelling time and congestion following a disturbance such as a platform delay. With the function defined, the problem resolves into finding a set of optimum arrival and departure times (the decision variables) that minimizes this penalty function. Ultimately, the concept is intended to form part of an on-line, real-time traffic controller residing on the despatching computer in a control centre. An embedded simulation is used to perform the optimization calculations, and several techniques are described that reduce the computing time needed to a level feasible for on-line use. Comparisons are made with some previous control algorithms. Using data based on the Hong Kong Island Line, it is shown that the new controller performs well, albeit when using the newly proposed evaluation function as the test criterion.