Iowa Code Title VIII. Transportation [Chs. 306-330B] § 321.431. Performance ability

1. The service brakes upon any motor vehicle or combination of motor vehicles, when upon dry asphalt or concrete pavement surface free from loose material where the grade does not exceed one percent, when traveling twenty miles per hour shall be adequate:

2. Under the conditions specified in subsection 1, the hand brake shall be adequate to hold the vehicle or vehicles stationary on any grade upon which operated.

3. Under the conditions specified in subsection 1, the service brakes upon a motor vehicle equipped with two-wheel brakes only, and when permitted under this section, shall be adequate to stop the vehicle within a distance of forty-five feet and the hand brake adequate to stop the vehicle within a distance of fifty-five feet.

4. All braking distances specified in this section shall apply to all vehicles mentioned, whether such vehicles are not loaded or are loaded to the maximum capacity permitted under this chapter.

5. All brakes shall be maintained in good working order and shall be so adjusted as to operate as equally as practicable with respect to the wheels on opposite sides of the vehicle.

6. A person who violates this section commits a simple misdemeanor punishable as a scheduled violation under section 805.8A, subsection 3, paragraph “ae”.