ATC / Cab Signals

Automatic Train Control & Cab Signals

Coded track circuit signaling displaying signal aspects and speed ceilings directly inside the cab.

Driving Difficulty Level 3 / 5

Intermediate

Based on vigilance required, reaction window, and braking penalty severity.

menu_book System Overview

Used widely across the Northeast Corridor (Amtrak, Metro-North, LIRR, NJ Transit) and commuter networks, Cab Signals transmit signal aspects through AC track currents directly into locomotive receiver coils.

settings How It Operates

check_circle The in-cab Aspect Display Unit (ADU) displays real-time track indications (Clear, Cab Speed, Approach Medium, Approach, Restricting).
check_circle ATC monitors that the engineer does not exceed the maximum speed authorized by the current cab signal aspect.
check_circle If the cab signal drops to a more restrictive aspect, an audible alarm sounds and the engineer must acknowledge within 6-8 seconds and initiate suppression braking.
check_circle Failure to slow down below the target speed curve results in an automatic penalty brake.

visibility In-Cab Visual & Audio Indications

notifications Aspect Display Unit (ADU)

Cab display showing signal aspect colors and digital speed limit.

notifications Continuous Warning Whistle

Air whistle or electronic tone sounding until acknowledged and braking begins.

lightbulb Driver Tips to Avoid Penalty Brakes

verified Cab signals take precedence over lineside visual signals in cab signal territory.
verified When entering a lower speed block, quickly apply brake handle to the "Suppression" notch to satisfy the system.

route Compatible Routes

All Routes arrow_forward

No specific routes mapped yet for this system in the database.