A multimodal approach to bus frequency design

In this paper we propose a model for optimising bus frequencies under the assumption of elastic demand, considering explicitly the effects of changes in transit supply on modal split. Indeed, neglecting demand elasticity may lead to solutions that may not represent actual design objectives. Using an objective function that is a weighted sum of user costs on all transportation systems (car and bus), operation costs and external costs, we propose a heuristic solution algorithm that is able to solve the problem in acceptable computing times, also for real-scale problems. The model and the algorithm are tested on a large urban multimodal network.