Regulations last checked for updates: Jan 30, 2025

Title 49 - Transportation last revised: Jan 27, 2025
Appendix Appendix B -

[This is a summary—see body of text for complete requirements]

Flagger for each direction of traffic Police officer present Flagger present, but not one for each direction of traffic No flagger/no police
False ActivationNormal SpeedNormal SpeedProceed with caution—maximum speed of 15 mphProceed with caution—maximum speed of 15 mph.
Partial Activation*Normal SpeedNormal SpeedProceed with caution—maximum speed of 15 mphProceed with caution—maximum speed of 15 mph.
Activation Failure**Normal SpeedNormal SpeedProceed with caution—maximum speed of 15 mphStop: Crewmember flag traffic and reboard.

*Partial activation—full warning not given.

Non-gated crossing with one pair of lights designed to flash alternatively, one light does not work (and back-lights from other side not visible).

Gated crossing—gate arm not horizontal; or any portion of a gate arm is missing if that portion had held a gate arm flashing light.

**Activitation failure includes—if more than 50% of the flashing lights on any approach lane not functioning; or if an approach lane has two or more pairs of flashing lights, there is not at least one pair operating as intended.

source: 61 FR 31806, June 20, 1996, unless otherwise noted.