South Dakota OS/OD Overview
Permit Required
Yes – any load exceeding legal size or weight must have a permit from the South Dakota Department of Transportation (SDDOT). Single-trip and annual permits are issued through SDDOT's online oversize/overweight permitting system at SDTruckInfo.
Legal Limits (Without Permit)
- Width: 8'6"
- Height: 13'6"
- Length: 75' (combo); 53' trailer allowed
- Weight: 80,000 lbs GVW (standard axle limits apply)
Anything over a legal dimension or weight requires an oversize/overweight permit before the move. Loads beyond routine permit limits may require route review and possible structure analysis.
Travel Hours
- Daylight only: Sunrise-to-sunset travel is required when width exceeds 10', height exceeds 14'6", or a single-unit exceeds 45' (SD Admin. Rules 70:03:01).
- Night travel: Generally not permitted for loads exceeding those daylight thresholds; verify lighting and route conditions on the issued permit.
Escort Requirements
| Dimension | Escort Requirement |
|---|---|
| Width > 10' (Black Hills designated area) | Front (lead) escort required |
| Width > 16' (interstate routes) | Rear (chase) escort required |
| Width > 20' (2-lane state highways) | Front (lead) escort required |
Detailed Information
FRONT ESCORT (BLACK HILLS): A front escort is required for widths over 10' within the Black Hills designated area (SD Admin. Rules 70:03:01).
REAR ESCORT (INTERSTATE): A rear civilian escort is required on interstate routes for widths over 16'.
FRONT ESCORT (2-LANE): A front civilian escort is required on 2-lane state highways for widths over 20' (70:03:01).
RESTRICTED TRAVEL: Movement is limited to sunrise-to-sunset when the load width exceeds 10', height exceeds 14'6", or a single-unit exceeds 45' (SD Admin. Rules 70:03:01).
Additional Notes
- "Oversize Load" signs, red/orange flags, and amber warning lights are required on the load and escort vehicles per SDDOT permit conditions.
- Permit conditions issued by SDDOT govern the specific move and may impose requirements beyond these general thresholds.
Source: South Dakota DOT — SDTruckInfo (Oversize/Overweight Permits). Informational only — always verify against the live permit office before any move; permit conditions control.
