Current textIn force on Nov. 8, 2021Source: eCFR
§ 393.81 Horn.
Current wording, in the annual edition revised as of Oct. 1, 2006.
49 CFR § 393.81 — Horn.. Text in force on November 8, 2021. This wording effective October 1, 2006 to present. Source: eCFR as of November 8, 2021, https://www.ecfr.gov/on/2021-11-08/title-49/section-393.81. Retrieved from FMCSR.com, https://fmcsr.com/reg/393.81?asof=2021-11-08, on October 26, 2026. Unofficial compilation; verify against the official source.
Every bus, truck, truck-tractor, and every driven motor vehicle in driveaway-towaway operations shall be equipped with a horn and actuating elements which shall be in such condition as to give an adequate and reliable warning signal.
Amendment history
2 distinct wordings on file since Oct. 1, 1996- Oct. 1, 1996 → Oct. 1, 2006annual editions 1996–2005
A new entry appears whenever the regulatory words change between government snapshots. Day-precise from the eCFR (2017 onward); before that, one snapshot per annual CFR edition (revised as of October 1). Bracketed citations are the Federal Register history printed with the section.