On a Track Authority outside CTC territory, SW - N will be used to indicate:

• A. The Foul Zone of the switch is not included in the limits
• B. The Foul Zone of the switch is included in the limits
• C. The Foul Zone is not applicable to this movement
• D. The movement is restricted to the main track only

Answer: (A)

The key idea here is how Track Authority defines what a movement can and cannot occupy around a switch. The SW - N notation signals that the foul zone around the switch is not included in the limits of the movement. In other words, the authority does not cover the area immediately around the switch where a train could foul the switch mechanism or interfere with the adjacent track. Because of that, the crew must treat that zone as outside the movement’s controlled limits and obtain separate protection or clearance if they need to operate near or through the switch. This is why the correct interpretation is that the foul zone is not included in the limits.