IEEE 1474.3-2025

This recommended practice establishes a preferred system design and functional allocation for CBTC systems.

The purpose of this recommended practice is to define a preferred CBTC system design/system architecture to achieve the CBTC performance and functional requirements of IEEE Std 1474.1-2025, and to allocate functions to the major CBTC subsystems.

Revision Standard - Active. Communications-based train control (CBTC) system design and functional allocations from IEEE Std 1474.1-2025 are built upon in the recommended practice by decomposing each identified automatic train protection, automatic train operation, and automatic train supervision function to a level where each subfunction can be allocated to one of the CBTC subsystems.