Users of highways within the City limits of the City of Phoenix which are within the State highway system and under the jurisdiction of the State of Arizona shall comply with the requirements of State law and upon such compliance are exempt from this division. This division shall not apply to fire apparatus, urban mass transit transportation system vehicles, or to implements of husbandry, including farm tractors temporarily moved upon a highway. (Ord. No. G-2130, § 2; Ord. No. G-2917, § 1)