If a motor vehicle and other vehicles are operated in combination during the time that lights are required under Section 41-6a-1603, a lamp that is obscured by another vehicle of the combination is not required to be lighted.
Utah Code § 41-6a-1605
Vehicles operated in combination
Renumbered and Amended by Chapter 2, 2005 General Session
Official source: Utah State Legislature. Reproduced from public-domain Utah statutes; confirm against the official source for the current text. Not legal advice.