A.R.S. § 28-702.04: Interstate Speed Limit

28-702.04. Maximum speed limit on interstate highways outside urbanized areas and within certain counties; definition

A. Except as provided in subsections C and D of this section, the speed limit for all types of motor vehicles is sixty-five miles per hour on the interstate system highways located outside of an urbanized area with a population of fifty thousand or more persons, except that the director may declare a lower speed limit on the highways pursuant to section 28-702.

B. A person shall not drive a motor vehicle at a speed in excess of the maximum speed limit prescribed by this section.

C. The director may order the increase of the maximum speed limit prescribed in subsection A of this section to seventy-five miles per hour on an individual interstate system highway subject to this section or on all of the interstate system highways in this state as prescribed in section 28-702.

D. The speed limit for all types of motor vehicles is at least sixty-five miles per hour on the interstate system highways located in a county that has a population of three million or more persons unless all of the following apply:

1. A reduction in the speed limit for operational efficiency is necessary as determined by a department-approved third-party engineering study or road safety assessment.

2. An opportunity for public input is provided.

3. The overall system capacity and transportation mobility will not be reduced.

E. A violation of this section is a civil traffic violation, and the person is subject to a civil penalty that does not exceed the amount provided by section 28-1598.

F. For the purposes of this section, "urbanized area" means an urbanized area as defined in the decennial census by the United States bureau of the census.