Car speed limits in South Dakota (2026)
Last reviewed: 9 October 2026
In short: The maximum lawful speed is 25 mph in unposted urban areas, 15 mph when passing a school at school times, 55 mph on township roads and 65 mph on other streets and highways. The limit is 80 mph on interstate highways, and up to 70 mph may be set on rural divided four-lane state trunk highways. Speeding fines are doubled in posted highway work areas while workers are present.
| Rule | What applies |
|---|---|
| Built-up areasPassenger car on public roads | 25 mph in urban areas that are not zoned or posted [1] |
| Outside built-up areas (single carriageway)Passenger car on public roads | 65 mph on any street or highway, except as provided for interstates or under speed zones set under § 32-25-7; 55 mph on township roads [1] |
| Outside built-up areas (dual carriageway or expressway)Passenger car on public roads | The Transportation Commission may set a maximum of 70 mph on any divided four-lane highway in a rural area on the state trunk highway system; signs must be posted [1] |
| MotorwaysPassenger car on public roads | 80 mph on the national system of interstate highways, except as provided under § 32-25-7 (speed zones) [1] |
| School zonesPassenger car on public roads | 15 mph when passing a school during school recess or while children are going to or leaving school at opening or closing hours. [1] |
| Roadworks zonesPassenger car on public roads | The Secretary of Transportation may set posted limited speed zones through highway work areas on state trunk highways. A speeding fine there while workers are present is double the usual fine, up to the Class 2 misdemeanour maximum. [1] |
Sources
- South Dakota Legislative Research Council: South Dakota Codified Laws chapter 32-25, Speed Regulation (sections 32-25-1.1, 32-25-4, 32-25-7.1, 32-25-9.2, 32-25-12) (consulted 9 October 2026) · all sources
South Dakota and neighbouring states
| State | Built-up areas | Outside built-up areas (single carriageway) | Outside built-up areas (dual carriageway or expressway) | Motorways |
|---|---|---|---|---|
| South Dakota | 25 mph unposted | 65 mph; 55 mph township roads | Up to 70 mph where set and posted | 80 mph |
| Iowa | 20 mph business, 25 mph residential | 55 mph | 65 mph (divided, multilane) | 70 mph (interstates) |
| Minnesota | 30 mph | 55 mph | 65 mph | 70 mph (65 in urban areas) |
| Montana | 25 mph | 70 mph day / 65 night | 75 mph day / 70 night | 80 mph (65 in urban areas) |
| North Dakota | 25 mph | 55 mph; 65 mph if posted | 70 mph | 80 mph |
| Nebraska | 25 mph residential, 20 business | 50-65 mph depending on road type | 65-70 mph | 75 mph (65 in parts) |
| Wyoming | 30 mph | 70 mph state highways; 65 mph other paved | — | 75 mph; 80 mph where designated |
More rules in South Dakota
- CannabisPossession for personal use: Criminal offence (misdemeanour up to 2 oz)
- Minimum age for a car driving licenceMinimum age for a car licence: 16 (operator's licence) · Earliest age to drive a car supervised: 14 (instruction permit)
- E-bikes and speed pedelecsLegal class: Three classes · Minimum age: Class III: 16
- FireworksConsumers may buy and use category F2 fireworks: Yes
- Knives and pepper sprayFolding pocket knives: Only concealment with felony intent
- Statutory minimum wageNational statutory minimum wage: Yes (state law) · Current adult minimum wage (gross): $11.85 per hour
- Using a mobile phone while drivingHolding a phone while driving banned: No (calls allowed) · Hands-free use: Allowed
- Seat belts and child seatsSeat belt compulsory in front seats: Yes · Seat belt compulsory in rear seats: Only passengers aged 5 to 17
- Tobacco and nicotine age limitsMinimum age to buy tobacco: 21 · Minimum age to buy e-cigarettes: 21
- Drinking age and alcohol salesMinimum age to buy beer and wine: 21+ (purchase, possess, consume) · Minimum age to buy spirits: 21+ (purchase, possess, consume)
- Drink-driving limitsBlood alcohol limit for ordinary drivers: 0.08% · Lower limit for novice or young drivers: 0.02% (under 21)
Related pages
General information, not legal advice. Rules change: check the official source before you fly or ride.