---
kind: "section"
citation: "49 C.F.R. § 218.23"
title: "49"
number: "218.23"
heading: "Blue signal display."
url: "https://uscodex.org/cfr/49/218.23"
---

# §218.23. Blue signal display.

- (a) Blue signals displayed in accordance with § [218.25](/cfr/49/218.25.md), [218.27](/cfr/49/218.27.md), or [218.29](/cfr/49/218.29.md) signify that workers are on, under, or between rolling equipment. When so displayed—
  - (1) The equipment may not be coupled to;
  - (2) The equipment may not be moved, except as provided for in [§ 218.29](/cfr/49/218.29.md);
  - (3) Other rolling equipment may not be placed on the same track so as to reduce or block the view of a blue signal, except as provided for in § [218.29 (a)](/cfr/49/218.29.md?p=a), [(b)](/cfr/49/218.29.md?p=b) and [(c)](/cfr/49/218.29.md?p=c); and
  - (4) Rolling equipment may not pass a displayed blue signal.
- (b) Blue signals must be displayed in accordance with § [218.25](/cfr/49/218.25.md), [218.27](/cfr/49/218.27.md), or [218.29](/cfr/49/218.29.md) by each craft or group of workers prior to their going on, under, or between rolling equipment and may only be removed by the same craft or group that displayed them.

## Notes

### Authority

Authority: 49 U.S.C. 20103, 20107, 20131, 20138, 20144, 20168; 28 U.S.C. 2461 note; and 49 CFR 1.89.

### Source

Source: 44 FR 2175, Jan. 10, 1979, unless otherwise noted.