An integrated capacity evaluation method for CBTC- system-equipped urban rail lines

Communications-based train control (CBTC) is an emerging technology for urban rail transit systems. An integrated method for assessing the capacity of CBTC-system-installed urban rail lines is proposed in this paper. Based on the UIC Code 406 method, the new integrated method includes train movement simulation, timetable construction, test and optimisation. In order to achieve an accurate blocking time, this paper introduces three operational scenarios, namely: consecutive running of trains, entering a station and turn-back at a terminal station. A practical timetable is implemented and optimised by simulating and evaluating the capacity with UIC Code 406. This paper considers Beijing’s Yizhuang metro line in a case study. It is found that a speed limit on the line produces a greater impact on the capacity compared with dwell time and switch speed restrictions. Furthermore, it is noted that a capacity bottleneck can easily occur during the process of entering a station and also during a turn-back operation at a terminal station.