Nothing in the Scenic Highway Zoning Act shall be construed to derogate from any powers of the state transportation commission under the Highway Beautification Act N.M. Stat. Ann. § 67-12-1 to 67-12-14 or the powers of the commission relating to the construction, repair or maintenance of highways or to require any act or omission on the part of the commission that is inconsistent with federal or state laws, regulations or policies. Nothing in the Scenic Highway Zoning Act shall be construed so as to affect or limit in any way any nonconforming use in existence on the effective date of the Scenic Highway Zoning Act or any ordinance adopted pursuant thereto.