NYC Subway Signals: A Complete Guide
15 hours ago
- New York City subway uses wayside color-light block signalling, with signals placed beside the track and utilizing colored lights.
- Tracks are divided into blocks via insulated joints; train presence is detected by short-circuiting rails, affecting signal control lengths.
- Signals have control lengths ensuring safe separation between trains, with automatic train stops enforcing compliance to prevent collisions.
- Interlocking coordinates signals and switches, typically managed by human operators to route trains safely around switch areas.
- The guide covers various signal types, including approach, automatic, marker, home, and holdout signals, along with train stops and time signals.
- Single-line diagrams and the NXSYS simulator are tools for understanding and simulating subway signalling systems.
- Signalling principles have remained largely unchanged since 1904, though in-cab and radio-based technologies are being gradually deployed on some lines like the 'L'.