Illinois OSOW permits

Updated: Sep 2

Permits valid for five days.

Illinois permitting system:

Contact phone number: 1-217-785-1477


Permit loads up to 12' wide, up to 13'6" high, up to 115' in length, up to 120,000 pounds (or 100,000 pounds on 5 axles) can now travel seven days a week, one-half hour before sunrise to one-half hour after sunset. Loads exceeding these dimensions are allowed to travel one-half hour before sunrise to one-half hour after sunset Monday through Friday, and one-half hour before sunrise until noon on Saturday. Overweight only are allowed continuous travel if the permit shows all other dimensions as legal.


Permit loads on Expressways in Cook County are restricted to a maximum of 120,000 pounds, 12' wide and/or 13'6". Several special restrictions apply in Cook County, as listed on provision sheets (General Provisions B). Loads over 14'6" wide up to and including 16' wide are limited to the hours of 9:00 a.m. to 3:00 p.m. Monday through Friday in the following counties: Cook, DuPage, Lake, Kane, Madison, McHenry, Monroe, St. Clair, and Will. Over 16' wide may have additional restrictions. No travel from noon the day before major holidays or holiday weekends. (Check with Sammons Permit Office).

Illinois Toll Roads:

The maximum width is 10' except 12' is allowed on sections that carry I-80 (near Indiana line) and US51 (near Wisconsin line). Gross weight 80,001 – 104,000 costs about $35.00; 104,001 – 120,000 is around $150.00. The maximum gross weight allowed is 120,000. Overall length exceeding 100' must have prior approval and a special permit. Maximum height is 14'6"; over 13'6" are $15.00 extra.


Width: 8'6" on designated highways, 8' on non-designated

Height: 13'6"

Length: 53' semi-trailer* on designated highways, 65' overall on non-designated. *Kingpin to the center of rear axle not over 45'6", or needs to be permitted.

Overhang: 3' front, 4' rear

Weight: 80,000 Gross Single – 20,000 Tandem – 34,000 Tridem – 42,500


Length limitations do not apply (O/D permit not needed) for vehicles operated in the daytime, Monday through Friday, when transporting beams, poles, pipe, culvert, or other objects of a structural nature 80' or less in length (overall length 100' or less). Farm tractors and other implements of husbandry may be hauled without a permit during daylight hours (including weekends) when over width only. A permit is still needed if over 13'6 high, or overweight.


Width: 14'6

Height: 15' (depending on overhead clearances, 3" clearance required)

Note: Height of 16' or more requires a detailed route survey.

Length: 145'

Weight Single – 24,000 Tandem – 48,000 Tridem – 60,000 (no single axle of group to exceed 21,000).

5 Axles – 100,000 6 or more Axles 120,000 (with Tridem drivers group not exceeding 48,000 pounds).

Note on Lift or Pusher axles: Maximum weight variance between axles in a group is 2,000 pounds.

Loads exceeding these dimensions or weight are considered as super loads. Loads exceeding 16' high require a route survey. Over 16' wide or 17' high will require a field or district engineering investigation. Over 17' high, all overhead utility companies must be contacted and documentation must be provided.


Width: Over 14'6 – 1 escort; over 16' – 3 escorts; over 18' – Illinois State Police escorts.

Height: Over 14'6 – 1 escort w/ high pole. Over 16' - route survey to get permit & 1 escort; over 18' – 2 escorts & State Police.

Length: Over 110' – 1 escort; over 145' – 3 escorts; over 200' – State Police.

Loads exceeding any two of the above dimensions – 2 escorts.


Lift axles are not considered for routine issuance. Blades, buckets, counterweights, etc. may be attached. Combination loads cannot be permitted for two over dimensions on two different pieces (example: cannot permit a load with an overwidth dozer and overheight backhoe on the same load).


Flags are required on the extremities of all oversize vehicles or loads and all protruding objects. "Oversize Load" signs are required on loads over 10' wide, 14'6 high, and/or 75' long. All oversize/overweight permit loads must display an operable oscillating, rotating, or flashing amber light or lights on the tractor. The size of the light(s) is not specified, but it must be visible from both sides and the front and must be strong enough to be seen for at least 500 feet in the daytime. When the visibility of the light is blocked from the rear, and for loads over 80' long or combinations over 100' long require a second light is required mounted 10' of the rear of the object, mounted as high as practical over it, is required.

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