In the context of Mandatory Directives, what does PSS stand for?

• A. Past Stop signal
• B. Public Safety Signal
• C. Past Stop Sign
• D. Past Safety Signal

Answer: (A)

In Mandatory Directives, PSS is the code used to identify a rail incident where a train has passed a stop signal. Past Stop signal literally flags that a train did not stop at a red signal and continued beyond it, which is a serious safety breach that requires immediate investigation and corrective action under the directive system. The term emphasizes that the event involves a signal that required stopping, not a sign or a different kind of safety indicator. The other options don’t fit because they would refer to signs or different concepts not used in this directive’s event coding.