321.316  Stopping.
  A person shall not stop or suddenly decrease the speed of a vehicle without first giving an appropriate signal in the manner provided in sections 321.314, 321.315, 321.317, and 321.318 to the driver of any vehicle immediately to the rear when there is opportunity to give such signal.
[S13, §1571-m18; C24, 27, 31, 35, §5032; C39, §5025.06; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §321.316]
2021 Acts, ch 80, §172
Referred to in §321.314, 805.8A(6)(p)
For applicable scheduled fine, see §805.8A, subsection 6