Locating New Stops in a Railway Network

Given a railway network together with information on the population and their use of the railway infrastructure, we are considering the e ects of introducing new train stops in the existing railway network. One e ect concerns the accessibility of the railway infrastructure to the population, measured in how far people live from their nearest train stop. The second e ect we study is the change in travel time for the railway customers that is induced by new train stops. Based on these two models, we introduce two combinatorial optimization problems and give NP-hardness results for them. We suggest an algorithmic approach for the model based on travel time and give rst experimental results.