Objective Under adverse weather conditions such as rain and snow, due to the lack of supporting emergency management strategies or system technical measures, the CBTC (communication-based train control) system is hard to ensure operational safety, posing certain safety risks. To address this issue, it is necessary to conduct research on systematic solutions.

Method A set of emergency management strategies for rainy and snowy weather is proposed, and its main contents are discussed. On this basis, two iterative upgrade technical schemes including Scheme 1 (functional decentralized implementation solution) and Scheme 2 (functional centralized implementation solution) are proposed based on the existing CBTC system. Train safety protection models under both rainy/snowy and non-rainy/snowy weather conditions are established for both schemes respectively. Based on these models, system-level function allocation and technical scenarios for both schemes are analyzed, and their feasibility and safety are discussed. Research and comparisons are conducted regarding the safety, feasibility, implementation cost, and operational efficiency of the strategies and schemes. Meanwhile, the selection of the average emergency braking deceleration value under rain and snow weather is systematically discussed.

Result & Conclusion  Since the proposed two technical schemes and a set of emergency management strategy have their respective advantages and disadvantages, different CBTC lines should select appropriate solutions based on their actual conditions. For lines without after-sales guarantee, it is recommended to adopt only the emergency management strategy. For newly built lines, Scheme 1 supplemented by emergency management strategies is recommended. While for old lines still within the warranty period, Scheme 2 supplemented by emergency management strategies is recommended.