Iowa's primary keep-right rule is found in Iowa Code §321.297.
A vehicle traveling at less than the normal speed of traffic at the time, place and under the conditions then existing must be driven in the right-hand lane available for traffic, or as close as practicable to the right-hand curb or edge of the roadway.
The slower-traffic rule does not apply when the driver is overtaking and passing another vehicle traveling in the same direction or when preparing for a left turn at an intersection, alley, private road or driveway.
Iowa also generally requires vehicles to be driven on the right half of the roadway, subject to exceptions for passing, avoiding obstructions, certain three-lane roadways and one-way traffic.
When overtaking another vehicle, the passing driver generally must pass on the left at a safe distance and may not return to the right until safely clear of the overtaken vehicle.
The driver being overtaken must generally give way to the right and may not increase speed until the passing vehicle has completely passed.
Exceptions
- Overtaking and passing another vehicle traveling in the same direction.
- Preparing for a lawful left turn at an intersection, alley, private road or driveway.
- Avoiding an obstruction when moving left is necessary and safe.
- Traveling on certain three-lane roadways under applicable lane rules.
- Traveling on a roadway restricted to one-way traffic.
Penalties
A violation of Iowa's keep-right rule is subject to a scheduled traffic fine under Iowa Code §805.8A.
Additional penalties may apply if the violation contributes to serious injury or death.
Drivers should verify the current amount shown on the citation or with the court handling the case because scheduled fines and assessments can change.
Official Source
Iowa Code §321.297 - Driving on Right-Hand Side of Roadway; Exceptions
Last verified: October 11, 2026