---
kind: "section"
citation: "49 C.F.R. § 393.19"
title: "49"
number: "393.19"
heading: "Hazard warning signals."
url: "https://uscodex.org/cfr/49/393.19"
---

# §393.19. Hazard warning signals.


The hazard warning signal operating unit on each commercial motor vehicle shall operate independently of the ignition or equivalent switch, and when activated, cause all turn signals required by [§ 393.11](/cfr/49/393.11.md) to flash simultaneously.


## Notes

### Amendments

[70 FR 48046, Aug. 15, 2005]

### Authority

Authority: 49 U.S.C. 31136, 31151, 31502; sec. 1041(b), Pub. L. 102-240, 105 Stat. 1914, 1993; secs. 5301 and 5524, Pub. L. 114-94, 129 Stat. 1312, 1543, 1560; and 49 CFR 1.87.

### Source

Source: 33 FR 19735, Dec. 25, 1968, unless otherwise noted.

### Amendments

[70 FR 48046, Aug. 15, 2005]