Rules-in-effect: ABS and CSS rules do not apply when which condition exists?

• A. The track is unpowered
• B. Non-signaled DCS rules are substituted for ABS
• C. The train is stopped
• D. The crew has a waiver

Answer: (B)

In NORAC operations, ABS and CSS guide train movement based on track signals and standard rules. They can be overridden when the dispatcher uses non-signaled DCS instructions, substituting those DCS rules for ABS. In that situation, the train must follow the dispatcher’s DCS directions rather than the normal signal-based rules until another ruling is issued. The other conditions—an unpowered track, the train being stopped, or a crew waiver—do not automatically suspend or replace ABS/CSS; they do not create a general override of the signal-based rules.