Illinois Oversize / Overweight Permit Requirements
Legal-without-permit dimension limits, escort and pilot car thresholds, height pole rules, daylight-only windows, and holiday restrictions for Illinois oversize moves.
Legal limits without a permit
In Illinois, 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 | 80,000 lb | Anything heavier |
Escort and pilot car thresholds
When permitted, the following escort or movement-restriction rules apply in Illinois. Thresholds are conservative — your specific permit conditions may impose tighter limits depending on the route.
| Trigger | Dimension | Threshold | Detail |
|---|---|---|---|
| Police escort | Length | 200'0" | State police escort required for overall lengths over 200' (92 Ill. Adm. Code 554.204). |
| Front pilot car | Length | 145'0" | Front pilot car required for combinations over 145' overall length on 2-lane highways. |
| Rear pilot car | Length | 110'0" | Rear pilot car required for combinations over 110' overall length. |
| Police escort | Width | 18'0" | State police escort required for widths over 18' on all highways (92 Ill. Adm. Code 554.204). |
| Police escort | Height | 18'0" | State police escort required for heights over 18' (92 Ill. Adm. Code 554.204). |
| Front pilot car | Width | 14'6" | Front pilot car required on 2-lane undivided highways when width exceeds 14'6" (554.208). |
| Rear pilot car | Width | 14'6" | Rear pilot car required on divided highways when width exceeds 14'6" (554.208). |
| Height pole | Height | 14'6" | Height-pole vehicle required when load exceeds 14'6" in height (92 Ill. Adm. Code 554.208). |
| Daylight-only movement | Width | 14'6" | Travel restricted to Mon–Fri sunrise–sunset and Sat sunrise–noon for widths over 14'6". |
| Weekend / holiday restriction | Width | 14'6" | No travel on New Year's Day, Memorial Day, July 4, Labor Day, Thanksgiving, or 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.