State has a Far Right as Practicable Requirement

A bicyclist traveling slower than normal traffic must ride as close as practicable to the right-hand curb or edge, except when passing, preparing for a left turn, or avoiding hazards (including a "substandard width lane" too narrow to share safely with another vehicle).

Allows Two Abreast Riding

South Dakota law does not address riding two or more abreast. Unlike Rhode Island, South Carolina, and Tennessee — each of which caps group riding at two abreast — South Dakota has no statute on point either way; a cyclist's road position is governed only by the general "as close as practicable to the right" rule in § 32-20B-5.

Single File is Required

State law does not require single-file riding. The only positioning rule, § 32-20B-5, requires riding as close as practicable to the right-hand edge, with the usual exceptions for passing, turning, and hazards.

Has a Safe Passing Law

A motorist overtaking a bicycle must leave at least three feet of separation where the posted speed limit is 35 mph or less, and at least six feet where it is higher than 35 mph, maintained until safely past. The motorist may partially cross the centerline or lane divider to comply if it can be done safely.

Helmets are required on the road

South Dakota has no general bicycle helmet law. A helmet is required only for a Class III electric bicycle operator under 18, and for any passenger on a Class III electric bicycle regardless of age (see eBikeRestrictions).

If Bike Lanes are present, they are required ( except when unsafe )

No South Dakota statute requires a bicyclist to use a bicycle lane or path when one is present.

Riders may use the sidewalks

South Dakota's general ban on driving a vehicle on a sidewalk expressly exempts bicycles (§ 32-26-21.1), and a bicyclist on a sidewalk or crosswalk has the rights and duties of a pedestrian, including yielding to pedestrians, giving an audible signal before passing one, and stopping before entering a crosswalk or highway from a sidewalk (§§ 32-20B-2, 32-20B-3). A municipality's local governing body may restrict or prohibit bicycles from its sidewalks.

Does the Impeding Statute Apply to Bikes

South Dakota's impeding-traffic statute is limited by its own terms to a "motor vehicle" and does not reach bicycles. No other South Dakota statute imposes a duty on bicyclists not to impede traffic. South Dakota has no separate statute applying the traffic laws to bicyclists, and needs none: its definitions count a bicycle as a "vehicle," so rules written for any vehicle bind a rider directly. This one does not, because it narrows itself to a "motor vehicle," which a human-powered bicycle cannot be.

Whether cyclists may treat stop signs as yield signs (the "Idaho stop").

South Dakota has not adopted a stop-as-yield ("Idaho Stop") law. Cyclists must obey stop signs and traffic signals the same as other vehicle operators.

Restrictions exist on e-bikes and usage

South Dakota defines three classes of electric bicycles by motor behavior and top assisted speed (20 mph for Class I/II, 28 mph for Class III), requires a manufacturer's label stating class, speed, and wattage, and requires the motor to disengage when the rider stops pedaling or brakes. Class III electric bicycles carry extra rules: riders must be at least 16, a helmet is required for any operator under 18 and any passenger regardless of age, a functioning speedometer is required, and use on many bicycle paths and trails is restricted unless the path is adjacent to a roadway or local authorities allow it.

Allows the concept of Contributory Negligence that allows any contributory fault resuls in 'no fault'

South Dakota uses a distinctive "slight/gross" comparative negligence rule by statute, not the 50%-or-51% threshold used by most other states: a plaintiff's own negligence bars recovery entirely unless it was "slight" compared to the defendant's, in which case damages are reduced proportionally rather than barred.