Upgrade pulls — minimum speed.

A motor vehicle or combination of vehicles, which cannot proceed up a three percent grade, on dry concrete pavement, at a minimum speed of twenty miles per hour, shall not be operated upon the highways of this state. [C39, § 5033.02; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §321.382 ] 83 Acts, ch 101, §70 Referred to in §321.23 , 805.8A(3)(f) For applicable scheduled fine, see §805.8A , subsection 3