Who must wear a helmet in South Dakota, the penalties for not wearing one, and the eye-protection rules every rider should know.
South Dakota has a partial motorcycle helmet law. Only operators and passengers under 18 are required to wear a protective helmet that meets US Department of Transportation Motor Vehicle Safety Standard 218 (SDCL 32-20-4). Riders 18 and older may legally ride without a helmet.
It is also illegal to operate a motorcycle with a passenger under 18 who is not wearing a helmet. The manual recommends a helmet for every rider regardless of the law.
Anyone under 18 — whether operating the motorcycle or riding as a passenger — must wear a DOT-compliant helmet.
Riders and passengers 18 and older are not required by South Dakota law to wear a helmet, though doing so greatly improves the odds of surviving a crash.
Operating or riding a motorcycle under 18 without a required helmet — or carrying an under-18 passenger who is not wearing one — is a Class 2 misdemeanor under South Dakota law. Confirm current fine amounts with the South Dakota Department of Public Safety.
Separate from and broader than the helmet rule, every motorcycle rider in South Dakota — at every age — must wear eye protection such as glasses or goggles, unless the motorcycle is equipped with a windshield of sufficient height (SDCL 32-20-4.1).
A windshield on the motorcycle satisfies this requirement, but most windshields will not protect your eyes from wind on their own. Tinted eye protection should not be worn when little outside light is available, such as at night.
A legal motorcycle helmet must meet the U.S. Department of Transportation (DOT) FMVSS 218 standard. Look for the "DOT" certification label on the back. Helmets that meet stricter Snell or ECE standards offer additional protection. Avoid novelty helmets — they are not legal head protection.
Source: Some test details are confirmed by the state agency; the rest reflect the consensus of major rider-education sources. dps.sd.gov states the written test must be passed at 80% or higher; the 25-question count is the third-party consensus. The manual is the standardized MSF Motorcycle Operator Manual, 18th Edition (June 2020), with a South Dakota DPS front section (Revised October 2020).