Optimization of emergency crossovers and signals for emergency operations in rail rapid transit

This paper presents a methodology for designing rail transit systems to meet operating requirements when track maintenance or failure cause sections of tracks to be unavailable for service. The methodology can be also used to establish the requirements for the continuity of operations during construction. The main objective of the paper is to develop a tool which performs trade-offs between system costs and level of services during emergencies/construction. Several alternatives, including various signal and control systems, number and types of crossovers and corresponding operating strategies, are developed and evaluated against capital investments. Operating measures and strategies for the selected alternative can be recommended before the design phase is completed, because the designer, by using this methodology, is aware of the capacities attained during emergencies and construction.