The transit network design problem with elastic demand and internalisation of external costs

In this paper we study the transit network design problem with elastic demand. We propose a multimodal optimisation model that considers an objective function equal to the sum of (car and transit) user costs, firm costs, external costs (air pollution, noise, etc.) and other social costs. In the proposed model external costs are considered in the objective function and optimised taking into account the effects of improving the LOS of transit system on modal share and, therefore, on the external costs. The proposed model is tested for optimising the services on a Regional Metro System.