StacksVerified U.S. regulatory reference

49 CFR §236.205

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The circuits shall be so installed that each signal governing train movements into a block will display its most restrictive aspect when any of the following conditions obtain within the block:
  1. (a)Occupancy by a train, locomotive, or car,
  2. (b)When points of a switch are not closed in proper position,
  3. (c)When an independently operated fouling point derail equipped with switch circuit controller is not in derailing position,
  4. (d)When a track relay is in de-energized position or a device which functions as a track relay is in its most restrictive state; or when signal control circuit is deenergized.