The maximum speed limit on interstate highways is 80 mph (129 kph). There are exceptions in urban areas, which are posted near Sioux Falls, Rapid City and North Sioux City. On other highways, the maximum speed limit ranges from 55 to 70 mph (88 to 113 kph).
Seat Belts and Child Restraints
South Dakota law requires drivers and front seat passengers to use seat belts. A passenger restraint system is also required for infants and children (younger than 5 years old).
To help ensure the safety of law enforcement and other emergency & stopped vehicles as well as that of drivers, motorists are required to move over and slow down when passing any vehicle displaying amber or yellow flashing lights. On interstates, drivers must merge into the lane farthest from the stopped vehicle. On two-lane highways, drivers must slow to a speed limit that is at least 20 mph (32 kph) slower than the posted speed limit.
It is unlawful for a person under 18 years of age to drive or ride on a motorcycle unless that person wears an approved safety helmet. Eye protection devices must be worn by all operators and passengers of all motorcycles.
The operator of every motor vehicle involved in an accident in which there is a death, personal injury or damage to any one person's property of $1,000 or combined damage to property of $2,000 shall immediately report the matter to the nearest available peace officer who has jurisdiction.
The legal drinking age is 21 for consumption of alcoholic beverages. Malt beverages are available on- and off-sale 7 a.m. to 2 a.m. Monday through Sunday morning. On Sundays, liquor and wine are sold on-sale in restaurants only, 11 a.m. to midnight. Package liquor sales on Sunday are allowed only by city or county ordinance. Open consumption is prohibited unless specifically allowed at or because of select events. Some Native American reservations are alcohol-free environments. Please check with tribal offices before importing alcohol onto reservations.