Under Rule 529A activation failure at a road crossing with one properly equipped flagman, what speed is allowed for the head end to pass?

• A. 25 MPH
• B. 15 MPH
• C. 30 MPH
• D. 40 MPH

Answer: (B)

When a crossing’s protective signals fail to activate, the crossing becomes guarded only by a flagman. In that situation, movement through the crossing must be done at a restricted, low speed so the engineer can stop safely if the flagman signals danger or if any hazard appears. The head end is allowed to pass at 15 mph under Rule 529A with one properly equipped flagman. This slower speed provides the necessary stopping time and reaction margin while the flagman maintains protection and clear signals. Higher speeds would reduce the ability to stop in time if a vehicle or other hazard is encountered, so they are not permitted in this scenario.