StacksVerified U.S. regulatory reference

49 CFR §236.825

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
A system so arranged that its operation will automatically result in the following:
  1. (a)A full service application of the brakes which will continue either until the train is brought to a stop, or, under control of the engineman, its speed is reduced to a predetermined rate.
  2. (b)When operating under a speed restriction, an application of the brakes when the speed of the train exceeds the predetermined rate and which will continue until the speed is reduced to that rate.