Dual-Objective Timetabling Method for Urban Rail Transit with Varying Express/Local Ratios

Express/local mode is an innovative approach in urban rail transit operations, offering regular service at all stations while providing high-speed service at certain stations. Since overtaking may occur in this special mode, the traditional timetable optimization method is difficult to apply. This study proposes a timetable optimization method for express/local mode. First, we designed a disassembly method of train departure cycles, which collapses the ratio of express/local trains into basic ratio types. Then, a timetabling model with this special mode, considering multiple transfer options of passengers, was established. The model aimed to reduce both the passenger waiting time at platforms and train energy consumption. Later, we designed a ratio-based adaptive differential evolution algorithm to deal with the proposed NP-hard problem. Numerical examples from Guangzhou Metro Line 14 were conducted. The results showed that the proposed model was able to reasonably allocate the capacity resources of trains and reduce passenger waiting time by 5.6% and train energy consumption by 9.4%.