South Dakota is wide-open trucking country. With I-90 spanning the state from the Minnesota border to the Black Hills, it is a prime corridor for heavy haul and Long Combination Vehicles (LCVs).
The South Dakota Department of Public Safety (DPS) has specific rules for these massive rigs. If you want to pull three trailers or haul the massive grain harvest, this 2026 guide is for you.
1. The LCV (Long Combination Vehicle) Factor
South Dakota is one of the few states where you will see Triple Trailers (a tractor pulling three 28.5-foot trailers).
- Endorsement: You need the Doubles/Triples (T) endorsement on your CDL.
- Permit: The company must have an LCV permit.
- The Skill: The most important skill is managing “Rearward Amplification” (Crack the Whip).
- The Rule: The heaviest trailer MUST be closest to the tractor. The lightest trailer MUST be in the rear. If you mess this up, the rear trailer will flip in a moderate curve.
2. South Dakota DPS CDL Fees (2026)
South Dakota fees are very reasonable.
| Item | Cost | Validity |
|---|---|---|
| Instruction Permit | $28.00 | 1 Year (plus 1 renewal allowed) |
| CDL License (Class A/B/C) | $33.00 | 5 Years |
| Endorsements | $15.00 | Per test/endorsement |
| Skills Test (Max Limit) | $90.00 | Third-party testers cannot charge more. |
3. Harvest Season & Ag Rules
In late summer/fall, South Dakota roads are filled with Custom Harvesters.
- Non-Resident CDL: South Dakota issues Non-Domiciled CDLs for foreign workers (H-2A visa) coming to help with the harvest.
- Safety: These convoys move slowly. Commercial drivers must be patient.
- Weight: There are seasonal weight exemptions for moving grain from field to elevator, but you must know the specific bridge limits.
4. Prairie Hazards: Wildlife
Driving I-90 at night is risky due to deer and antelope.
- The Rule: DO NOT SWERVE.
- Why? If you are pulling doubles or triples, swerving to miss a deer will almost certainly cause the rear trailers to whip and rollover. Brake firmly, stay in your lane, and hit the animal if you cannot stop. A damaged bumper is better than a flipped road train.
5. SD Practice Questions
The heaviest trailer must always be closest to the tractor. This anchors the combination. Putting a heavy trailer at the rear acts like a pendulum and will cause instability.
Triples have a huge surface area and more articulation points. They are extremely susceptible to being blown over. If wind advisories are up, park it.
Conclusion
South Dakota is a great state for experienced drivers who want to handle big gear. Master the ‘T’ endorsement and respect the winter plains to succeed here.