STOCHASTIC OPTIMIZATION IN COMPUTING MULTIPLE HEADWAYS FOR A SINGLE BUS LINE

We consider the problem of computing multiple headways for a single bus line to maximize the expected daily profit. The stochastic bus-line model assumes that (1) the passenger arrivals follow a Poisson process with possible reneging; (2) the number of alighting passengers at each stop follows a binomial distribution; and (3) the bus travel time follows a Weibull distribution. The objective function, the expected daily profit defined as the ticket revenue minus the operating and customer waiting costs, is discontinuous at changes in the bus frequency. For this stochastic optimization problem, we propose a retrospective optimization algorithm that can handle both homogeneous and nonhomogeneous Poisson arrivals. Simulation results are discussed