Objective Addressing the problems of insufficient fault localization accuracy, lagging handling response, and high reliance of fault handling on the experience of operations and maintenance personnel in FAO （fully automatic operation） and CBTC （communication-based train control） systems, it is necessary to research an emergency braking handling model for urban rail transit signaling systems based on decision trees.

Method Relying on the line emergency braking fault dataset and on-site handling records, a cause analysis is conducted to classify faults into three categories: signaling-dominated faults, vehicle-associated faults, and external interference and human factors, sorting out the triggers for each type of fault. Combining the coupling of fault factors and chronological logic, integrating industry expert experience, and adhering to four design criteria, a three-level decision tree braking model is constructed. With DMI （driver-machine interface） alarm information as input, the primary branch distinguishes FAO and CBTC systems; the secondary branches trace back layer by layer around ATP （automatic train protection） systems, wayside ATP systems, ATO （automatic train operation） systems, and non-signaling linkage faults; and the tertiary nodes output standardized handling operations.

Result & Conclusion  The three-level tree structure enables multi-dimensional fault tracing, with all nodes adopting binary logic, making the reasoning process fully interpretable. The proposed emergency braking handling model can establish a mapping relationship between alarm information and handling strategies; all types of fault triggers can be mapped to leaf nodes for precise localization, solidifying expert rules and forming a closed-loop process from fault tracing to handling instruction output.