StacksVerified U.S. regulatory reference

49 CFR §236.751

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
An arrangement of signals and signal appliances operated from an interlocking machine and so interconnected by means of mechanical and/or electric locking that their movements must succeed each other in proper sequence, train movements over all routes being governed by signal indication.