Which term defines a speed at which a train can be stopped short of another train or obstruction?

• A. Limited Speed
• B. Maximum Authorized Speed (MAS)
• C. Restricted Speed
• D. Medium Speed

Answer: (D)

This question tests recognizing the speed category that requires the ability to stop the train short of any obstruction. The term that captures this safety requirement is restricted speed. It means you operate at a pace where you must be able to bring the train to a stop within the distance you can see ahead and be prepared to stop for any train, obstruction, or stop signal. This is the speed discipline used when visibility is limited or when approaching signals and equipment where stopping promptly is essential for safety.

Maximum Authorized Speed is simply the highest speed permitted on the track segment under current conditions; it isn’t specifically about stopping within sight distance. Limited Speed is a broader designation used for various temporary or condition-based restrictions and doesn’t convey the explicit need to stop within the observed distance. Medium Speed isn’t a formal term used in standard railroad rules.