What "South Dakota traffic law" actually covers
South Dakota's vehicle code regulates speed, right-of-way, signaling, lane use, parking, equipment, insurance, alcohol, and the documents you must carry while driving. Most of the questions on the South Dakota permit exam come from a few sections of that code — speed and right-of-way alone account for nearly a third of the test. The SD DPS publishes a free PDF handbook that summarizes the relevant sections in plain language; this page condenses the parts that show up on the knowledge test.
Speed limits at a glance
In South Dakota, expect 80 mph on rural Interstates, 65 mph on urban Interstates, 25 mph in residential areas, and 15 mph in marked school zones when children are present. The basic speed law overrides every posted limit: you must drive at a speed that is reasonable for the weather, traffic, road, and visibility — even if that means going well below the posted number in fog or heavy rain.
For a deeper read on this topic across all 50 states, see our right-of-way, speed limits, and alcohol and drugs articles.
Right-of-way essentials
At a four-way stop the first vehicle to arrive proceeds first; if two arrive together, the one on the right goes. At an uncontrolled intersection, yield to any vehicle already in the intersection and to the vehicle on your right when arrivals are simultaneous. Pedestrians in any marked or unmarked crosswalk always have right-of-way in South Dakota, and emergency vehicles with lights and siren require you to pull to the right and stop.
Alcohol, drugs, and implied consent
The legal BAC limit in South Dakota is 0.08% for drivers 21 and older, 0.02% for drivers under 21, and 0.04% for any driver operating a commercial vehicle. By accepting a South Dakota driver license or permit you give implied consent to chemical testing — refusing the breath, blood or urine test triggers an automatic license suspension separate from any DUI conviction.
Phones, seat belts, and child seats
Handheld phone use while driving is illegal in South Dakota. Texting while driving is illegal for all drivers regardless of age. Seat belts are required for primary enforcement for all front-seat occupants. Children must be in an approved restraint until they meet the South Dakota height-and-weight thresholds — currently required for children under 8 or under 4'9".
Quick facts about South Dakota
- Capital: Pierre
- Minimum permit age: 14
- Current permit fee: $28
- Supervised hold period: 6 months
- Adult BAC limit: 0.08% · Under-21 BAC: 0.02%
- Default speed limits: 80 mph rural Interstate, 65 mph urban Interstate, 25 mph residential, 15 mph school zone
- Handheld phone use: banned
- Vision standard: 20/40 acuity in at least one eye, corrected or uncorrected
- Reinstatement fee after suspension: $50
- Official source: SD DPS
Other South Dakota guides on PermitPrep
Each link below opens a dedicated South Dakota page. Every guide is built from the same official SD DPS handbook so the rules stay consistent across topics.
- South Dakota Permit Practice Test — Practice test for South Dakota drivers.
- South Dakota Driving Permit Guide — Permit guide for South Dakota drivers.
- South Dakota Road Signs Test — Signs test for South Dakota drivers.
- South Dakota Right-of-Way Rules — Right of way for South Dakota drivers.
- South Dakota Speed Limits Explained — Speed limits for South Dakota drivers.
- South Dakota DUI Laws — DUI laws for South Dakota drivers.
- South Dakota Cell Phone Laws — Cell phone laws for South Dakota drivers.
- South Dakota Parking Rules — Parking for South Dakota drivers.
Ready to test what you have learned? Take the free South Dakota permit practice test — 20 randomized questions, instant grading, full explanations.