Michigan Oversize / Overweight Permit Requirements
Legal-without-permit dimension limits, escort and pilot car thresholds, height pole rules, daylight-only windows, and holiday restrictions for Michigan oversize moves.
Legal limits without a permit
In Michigan, you can move a load without an OSOW permit up to these dimensions on the Interstate and designated highways. Anything over the limits requires a permit (and may require escorts — see below).
| Dimension | Without a permit | Permit required when |
|---|---|---|
| Width | 8′6″ (federal limit) | Anything wider |
| Height | 13′6″ | Anything taller |
| Combo length | 75′0″ | Anything longer |
| Gross weight | 164,000 lb | Anything heavier |
Escort and pilot car thresholds
When permitted, the following escort or movement-restriction rules apply in Michigan. Thresholds are conservative — your specific permit conditions may impose tighter limits depending on the route.
| Trigger | Dimension | Threshold | Detail |
|---|---|---|---|
| Front pilot car | Length | 100'0" | Front + rear pilot cars required for combinations over 100' overall length. |
| Rear pilot car | Length | 90'0" | Rear pilot car required for combinations 90'–100' overall length. |
| Height pole | Height | 15'0" | Front + rear pilot cars required above 15'; front escort with height pole required at 14'5"–15'. |
| Rear pilot car | Rear overhang | 15'0" rear overhang | Rear pilot car required when rear overhang exceeds 15'. |
| Front pilot car | Width | 14'0" | Front + rear pilot cars required for widths over 14' (R. 247.167). Rear only for 12'–14'. |
| Rear pilot car | Width | 12'0" | Rear pilot car required when width is 12'–14' (R. 247.167); front added above 14'. |
| Daylight-only movement | Width | 12'0" | Sunrise-to-sunset travel only on weekdays; no weekend travel when width exceeds 12' or height exceeds 14'. |
| Weekend / holiday restriction | Width | 12'0" | No travel on New Year's Day, Good Friday, Memorial Day, July 4, Labor Day, Thanksgiving, Christmas. |
Stop tracking these rules by hand.
OverSizeTMS encodes the per-state escort and dimension rules for every state plus DC. Enter the load dimensions and route, and the platform tells you which permits, escorts, and time windows apply automatically.
See how it works →Last updated 2026-06-06. Cross-checked against the state admin code.