What action does a speed dial exclusion indicate?

A speed dial exclusion indicates that a service brake application has been triggered by the car-borne Automatic Train Control (ATC) system. This mechanism is designed to ensure safety by managing train speeds in response to various operational conditions. When the ATC detects a situation warranting a reduction or elimination of speed, it will activate the brakes accordingly.

In this context, the speed dial exclusion serves as an important safety feature that helps to prevent accidents or unsafe conditions that could result from excessive speed. By automatically applying the brakes, the system ensures that the train operates within a safe speed limit, thus protecting both passengers and railway infrastructure. This response to specific scenarios highlights the proactive nature of modern train control systems in maintaining safety and compliance with operational parameters.