Integrating Robust Railway Network Design and Line Planning under Failures

Traditionally, when designing robust transportation systems, one wants to increase the functionality of the system in presence of failures, even though they might not work optimally when no failures occur, which is the usual case. In this paper we make an attempt to integrate robust network design and line planning without decreasing the efficiency of the system when no failures occur. Therefore, extra costs must be met (price of robustness). Two different concepts of robustness are considered: one from the user's point of view, which aims at minimizing total travel time, and one from the operator's point of view, which aims at minimizing extra costs, both assuming possible disruptions.