Transit interchange discount optimization using an agent-based simulation model.

Transit interchange discounts encourage people to travel by public transport, increasing the revenue of the operators. This research develops a transit assignment model, which takes account of the actual travel time, congestion and fare of the public transport, using an agent-based simulation model MATSim. Then, a simulation-based optimization problem is formulated to optimize the interchange discount to maximize profit. For computational efficiency, a metamodeling technique is further proposed and the metamodel can serve as a surrogate of the expensive simulation process. Transfer hubs are set up in a Hong Kong Island scenario and the interchange discount for bus-bus interchanges is optimized. The optimization result shows that the optimal interchange discount optimized by the proposed metamodel-based method increases the bus operators’ profit by 12%.