A MILP model for quasi-periodic strategic train timetabling

In railways, the long-term strategic planning is process of evaluating improvements to railway network (e.g., upgrading a single track line double line) and changes composition/frequency train services adding 1 per hour along certain route). The effects different combinations infrastructure upgrades updated (also called scenarios), are usually evaluated by creating new feasible timetables followed extensive simulation. Strategic Train Timetabling (STT) indeed task producing tentative for these what-if scenarios. Unlike more classic timetabling, STT can often overlook (or at least give less importance to) some complementary aspects, such as crew rolling stock scheduling. On other hand, scenarios likely lead very timetables, hindering common effective practice using existing warm start solution process. We introduce concept quasi-periodic that where subsets trains need almost (rather than precisely) same minute every period. additional flexibility offered turned out be crucial in real-life characterized elevated traffic. describe MILP based approach timetabling we test it on 4 realistic an important Norway. produced our algorithm were ultimately used Norwegian Railway Directorate select 3 phasing progressive expansion J?ren line.