Robust and optimized urban rail timetabling using a marshaling plan and skip-stop operation

Urban rail transit (URT) demand often exhibits tidal or centripetal shapes during peak/off-peak hours. Inefficiency occurs when the supply of service is not adjusted to the fluctuating demand. This optimization can be realized by redesigning the URT timetables and/or through operational strategies. Certainly, implementation of the optimal/best-adjusted timetables must be feasible in order to accommodate efficient operations planning. This work develops a new methodology to derive an optimal timetabling design procedure for multiphase demands on a bi-directional URT line. It consists of three operational policies: marshaling, skip-stop operation, and robustness. The order of service is determined by the departure times. Following these considerations, this work develops a hybrid model formulated as a mixed-integer programming framework. The case study demonstrates the ability of the modeling framework to assess integrated effects, guarantee its robustness and to bring about 13% saving of the total cost associated with passengers, operations and reliability.