State comparison · Updated October 2026
North Dakota vs. South Dakota Driving Laws (2026)
North Dakota and South Dakota part ways on 2 of 9 topics we track: car sales tax and new resident deadline.
A drive from Fargo to Sioux Falls takes you across the border, and 2 of the rules change on the way. Key roads are I-94 on the North Dakota side and I-90 on the side of South Dakota; the capitals, Bismarck and Pierre, set the laws for each side.
The biggest gap: new residents face 60 days in North Dakota but 90 days in South Dakota ahead of the first deadline. Drivers based in Bismarck who drive to Rapid City, or the other way around, deal with both sets of rules: North Dakota's on I-29 and South Dakota's once they cross on I-29. Read the North Dakota vs South Dakota guide before driving from Fargo to Sioux Falls.
For a quick visit from Bismarck to Pierre, keep a helmet if you ride, set navigation before leaving, and expect the same 80 mph top limit after crossing.
| Topic | North Dakota | South Dakota |
|---|---|---|
| Max speed limit | 80 mph | 80 mph |
| Phone law | Texting ban only | Texting ban only |
| Learner's permit age | Permit at 14 | Permit at 14 |
| Car insurance | 25/50/25 | 25/50/25 |
| Car sales tax | 5% | 4% |
| Car inspection | No regular inspection | No regular inspection |
| New resident deadline | 60 days | 90 days |
| Helmet law | Under 18 | Under 18 |
| Lane splitting | Not allowed | Not allowed |
Driving laws side by side: North Dakota vs South Dakota
North Dakota vs South Dakota: South Dakota and North Dakota have the same rule for 80 mph for max speed limit, phone law: Texting ban only and Permit at 14 for learner's permit age.
Owning a car side by side: North Dakota vs South Dakota
North Dakota vs South Dakota: South Dakota and North Dakota have the same rule for car insurance: 25/50/25 and No regular inspection for car inspection.
Car sales tax: North Dakota vs South Dakota
North Dakota is higher on car sales tax: North Dakota at 5% and South Dakota at 4%. On a $30,000 car, state tax is around $1,500 in North Dakota and $1,200 in South Dakota. Buyers from Bismarck or Rapid City owe the tax of their home state.
New resident deadlines: North Dakota vs South Dakota
North Dakota is shorter on new resident deadline, with North Dakota at 60 days and South Dakota with 90 days. Anyone moving from Bismarck to Rapid City can book DMV appointments in advance.
Motorcycle compared: North Dakota vs South Dakota
North Dakota vs South Dakota: South Dakota and North Dakota agree on helmet law (Under 18) and Not allowed for lane splitting.
Moving or buying across the border
- North Dakota vs South Dakota: moving from North Dakota to South Dakota means 90 days to register the car and 90 days for the license switch.
- Moving from South Dakota to North Dakota: 90 days for registration and 60 days for a license.
North Dakota vs South Dakota: FAQ
Where can you drive faster, North Dakota or South Dakota?
Both North Dakota and South Dakota top out at 80 mph.
Is car tax lower — North Dakota or South Dakota?
South Dakota charges less at the state level (5% vs. 4%).
Is a motorcycle helmet mandatory in both North Dakota and South Dakota?
North Dakota: Under 18; South Dakota: Under 18.