FMSCA Regulation 356.13
356.13 Redesignated highways.
Where a highway over which a regular route motor common carrier of property is authorized to operate is assigned a new designation, such as a new number, letter, or name, the carrier shall advise the FMCSA by letter, and shall provide information concerning the new and the old designation, the points between which the highway is redesignated, and each place where the highway is referred to in the carrier's authority. The new designation of the highway will be shown in the carrier's certificate when the FMCSA has occasion to reissue it.
