Optimal Location of Railway Stations: The Lisbon-Porto High-Speed Rail Line

Rail transportation has experienced a rebirth in the last few decades, and a very large investment will certainly be made in new railway lines in the years to come---especially in high-speed rail lines. The success of such investment is heavily dependent on rail ridership, which in turn is dependent on the location of railway stations. In this paper, we present a mixed-integer optimization model that determines the optimal location and number of stations along a railway line that will be introduced over an existing transportation network. The stations are chosen within a set of possible locations defined a priori according to the objective of maximizing travel cost savings. The model takes into account the sensitivity of rail ridership to time losses because of stops at intermediate stations, as well as static competition from other modes. The practical usefulness of the model is illustrated with a case study involving a high-speed rail line expected to be built in Portugal in the future: the Lisbon-Porto line.