Illinois Oversize Load Permit Requirements
Legal truck dimensions, oversize load travel hours, pilot car and escort requirements, and how to order an oversize/overweight permit from IDOT Bureau of Operations, Permit Office.
IL, reviewed October 2026
Check your load for Illinois
Oversize permit required in Illinois
- Width 10 ft 0 in exceeds the 8 ft 6 in legal limit.
No width-based pilot car at 10 ft 0 in wide.
Illinois Truck Legal Width, Height & Length
A truck and load at or under these dimensions can travel Illinois highways without an oversize permit. Exceed any one of them and you need a permit before you move.
| Legal width | 8 ft 6 in |
|---|---|
| Legal height | 13 ft 6 in |
| Legal length | Semitrailer 53 ft on Class I/II designated highways; single truck 42 ft; tractor-semitrailer overall 65 ft on non-designated highways (no overall limit on Class I/II); doubles 28.5 ft per trailer on Class I/II (IDOT OPER 753). |
| Gross weight | 80,000 lbs |
Illinois Oversize Load Travel Hours
- Daily movement window
- Legal-size overweight: 24/7. Up to 12 ft wide, 13'6" high, 200 ft long: 24/7 (extra civilian escort at night). Up to 14'6" wide, 15 ft high, 200 ft long: 1/2 hr before sunrise to 1/2 hr after sunset, 7 days. Up to 16 ft wide, 17 ft high: sunrise-sunset Mon-Fri and until noon Saturday. Wider/taller than 16/17 ft: 9 am to 3 pm Mon-Fri.
- Weekend movement
- Loads up to 14'6" wide/15 ft high move 7 days a week in daylight; up to 16 ft wide/17 ft high Saturday until noon only; loads over 200 ft long or over 16 ft wide/17 ft high have no Saturday or Sunday movement unless the permit says otherwise.
- Holiday restrictions
- IDOT Permit Travel Restrictions 2026: noon Wed Dec 31 through sunrise Fri Jan 2; noon Sun May 24 through sunrise Tue May 26 (if travel normally allowed); noon Fri Jul 3 through sunrise Sun Jul 5; noon Sun Sep 6 through sunrise Tue Sep 8; noon Wed Nov 25 through sunrise Fri Nov 27; noon Thu Dec 24 through sunrise Sat Dec 26. Applies to all permit moves with any dimension over legal except over-width-only implements of husbandry. See this year's holiday dates for all states.
Illinois Pilot Car Requirements
One civilian escort is required for moves exceeding 14'6" wide, 14'6" high or 110 ft long; two (front and rear) if two of those are exceeded; three over 16 ft wide, 18 ft high or 145 ft long; ISP escort over 18 ft wide or high or 200 ft long.
| First pilot car (width) | 14 ft 6 in wide and over |
|---|---|
| Two pilot cars (width) | Not confirmed: check your permit conditions |
| Height-pole escort | Not confirmed: check your permit conditions |
| Length escort | 110 ft 0 in long and over |
Illinois pilot car requirements by load width and height. Crossing a border? Compare with Indiana, Iowa, Missouri.
How to order a Illinois oversize permit
IDOT Bureau of Operations, Permit Office
Overweight as well? Check axle limits with the bridge formula calculator.
Crossing Illinois without Illinois apportioned plates? Estimate the temporary trip permit cost with the trip permit cost estimator.
Illinois Oversize Load FAQs
- What are the oversize load travel hours in Illinois?
- Legal-size overweight: 24/7. Up to 12 ft wide, 13'6" high, 200 ft long: 24/7 (extra civilian escort at night). Up to 14'6" wide, 15 ft high, 200 ft long: 1/2 hr before sunrise to 1/2 hr after sunset, 7 days. Up to 16 ft wide, 17 ft high: sunrise-sunset Mon-Fri and until noon Saturday. Wider/taller than 16/17 ft: 9 am to 3 pm Mon-Fri. Weekends: Loads up to 14'6" wide/15 ft high move 7 days a week in daylight; up to 16 ft wide/17 ft high Saturday until noon only; loads over 200 ft long or over 16 ft wide/17 ft high have no Saturday or Sunday movement unless the permit says otherwise.
- When is a pilot car required in Illinois?
- One civilian escort is required for moves exceeding 14'6" wide, 14'6" high or 110 ft long; two (front and rear) if two of those are exceeded; three over 16 ft wide, 18 ft high or 145 ft long; ISP escort over 18 ft wide or high or 200 ft long.
- What is the legal truck width in Illinois?
- The standard legal width in Illinois is 8 ft 6 in (102 inches), the federal minimum width allowed on the National Network of highways. A load wider than that needs an oversize permit.
- How tall can a truck be in Illinois without a permit?
- The legal height limit in Illinois is 13 ft 6 in, measured from the road surface to the highest point of the vehicle or load. Taller loads need an oversize permit and a surveyed route for bridge and wire clearances.
- Can oversize loads move on holidays in Illinois?
- IDOT Permit Travel Restrictions 2026: noon Wed Dec 31 through sunrise Fri Jan 2; noon Sun May 24 through sunrise Tue May 26 (if travel normally allowed); noon Fri Jul 3 through sunrise Sun Jul 5; noon Sun Sep 6 through sunrise Tue Sep 8; noon Wed Nov 25 through sunrise Fri Nov 27; noon Thu Dec 24 through sunrise Sat Dec 26. Applies to all permit moves with any dimension over legal except over-width-only implements of husbandry.
- How do I get an oversize or overweight permit in Illinois?
- Apply through IDOT Bureau of Operations, Permit Office ((217) 785-1477) or its online permit portal. Have your USDOT number, vehicle and load dimensions, axle weights and route ready. Permit expediting agents can file on your behalf if you need the permit the same day.
Regulations change. This page summarises published Illinois rules as reviewed October 2026 and is not legal advice; the conditions printed on your permit control. Note: Escort thresholds are from OPER 993 provisions. Width alone triggers one escort at over 14'6" and three at over 16 ft; two escorts apply when a load exceeds two of the three dimension triggers, so escortTwoWidthFt is null. Holiday blackout dates are published per year; the Memorial/Labor Day window starts noon Sunday (not Friday). Legal width 8'6".