Transfer synchronization model with elastic headway and valid inequalities

Given that the timetable with even headway is inferior in matching the passenger demand, we use the departure times in even headway situation as the benchmarks, and allow the departure times to change within a limited range to increases the flexibility in timetabling. Then a transfer synchronization model with elastic headway is constructed. By analyzing the specific structure of the model, four classes of valid inequalities are designed to improve the computational efficiency when implementing the branch and cut algorithm in CPLEX. Finally, an experimental case study is conducted and results show that timetabling with elastic headway can effectively improve transfer efficiency, and valid inequalities can strengthen the linear relaxation model and shrink the solution space as well as the number of branch nodes, and then the algorithm can seek the optimal solution faster.