South Dakota's primary keep-right rule is found in South Dakota Codified Law §32-26-1.
On highways of sufficient width, drivers generally must operate on the right half of the highway.
A slow-moving vehicle must be driven as close as possible to the right-hand edge or curb of the highway.
The rule allows a driver to move left when overtaking and passing another vehicle, subject to South Dakota's passing laws.
The statute also recognizes situations where traveling on the right side is impracticable.
South Dakota may also designate specific lanes for slow-moving traffic by official signs, and drivers are required to obey those lane-use directions.
South Dakota therefore follows a general keep-right and slow-traffic model rather than a statewide rule making the far-left lane exclusively a passing lane on every multilane highway.
Exceptions
- Overtaking and passing another vehicle when permitted by law.
- Conditions where traveling on the right side of the highway is impracticable.
- Following official signs that designate another lane for particular traffic.
- Highway maintenance operations where equipment must use another part of the roadway.
Penalties
A violation of South Dakota Codified Law §32-26-1 is a Class 2 misdemeanor.
Violations of designated slow-traffic lane requirements under §32-26-8 are also classified as Class 2 misdemeanors.
The exact fine and total amount due may depend on the citation and applicable court costs or assessments.
Official Source
South Dakota Codified Law §§32-26-1 and 32-26-8 - Keep Right and Slow-Moving Traffic Rules
Last verified: October 11, 2026