Colorado OSOW permits

Updated: Sep 2

Permits valid for five days.

Colorado permitting system:

Contact phone number: 1-303-757-9539


Sunrise to Sunset. Up to 12' wide, night travel is allowed with proper lighting (see Signs, Flags, & Lights, below). Over 12' wide but not over 14' wide require an escort for night running.


Curfew times are shown on the addendum that accompanies an oversize permit. Eisenhower Tunnel on I-70: maximum overall height allowed is 13'11". Higher loads use US6 to bypass the tunnel. Over 11' wide permitted loads must pull over and call to get clearance to pass through the tunnel, but wider loads can use it. Loads into our out of Denver require a city permit for city streets, but Denver is very slow in turning them around (average 2-3 days).


Width: 8'6"

Height: 14' 6" designated highways, 13' non-designated.

Length: 57'4" trailer & load legal on an interstate or designated highways.

Overhang: 4' front, 10' rear. Over 4' rear needs lighting for night running (see Signs, Flags, & Lights, below)

Weight: 80,000 Gross on Interstate, 85,000 on non-Interstate. Steer – 20,000 Single – 20,000 Tandem – 36,000 Tridem – 54,000


Width: 17'

Height: No set limit.

Length: 130' (4-lane highways).

Weight: Single – 22,000-27,000 Tandem – 42,000-50,000 Tridem – 55,000-65,000 Quad – up to 72,000 max Maximum permitted weights depend on route classification and axle spacings. Loads exceeding 17' wide or 200,000 GVW are Super Loads.


Width: Interstate over 15' – 1 rear escort or one flashing yellow light in the rear. The following requirements apply to most routes ("Green Routes"); some smaller routes may require more: Two-lane highways: Width over 13' – 1 escort; over 15' – 2 escorts, or 1 front escort and flashing yellow light in the rear. Four-lane highways: Width over 13' – 1 rear escort or one flashing yellow light in the rear; over 15' - 2- escorts, or front escort and flashing yellow light in the rear.

Height: Over 16' – 1 escort with a high pole. Over 17'6" - route survey and utility clearance letters also required.

Length: Over 85' on some portions of 2 and 4-lane highways – 1 escort. Over 110' on 2-lane or over 115' on 4 or more lanes – 1 escort.

Overhang: Over 25' – 1 escort.

Note: All pilot car vehicles must be over 60" wide for CO.


The dozer blade can be detached and hauled with the dozer on the same trailer if the load would be overweight with or without the blade. Colorado Chain Law: All commercial vehicle truck-tractors operating on I-70 between Dotsero (milepost 133) and Morrison (milepost 259) between September 1st to May 31st must carry sufficient chains to be in compliance with the Colorado chain law. You can be fined for failure to comply. A permit is now available for overweight divisible loads on tractor/trailers with tandem, tridem, or quad trailer.


"Oversize Load" signs are required front and rear for all oversize loads. They are not required and should not be used for overweight only loads. Flags are required at all four corners of any extremities for wide and over length loads, and at the end of load projections greater than 4 feet. For night travel of wide loads, a flashing yellow light mounted on the front of the vehicle, and two or three mounted to Gary Bergman March 2012 the extreme rear are required. Over-length or with rear overhang (over 10') may run at night with a flashing yellow light mounted to the front of the vehicle and from one to three cluster lights mounted to overhang (red for rear overhang, yellow for front overhang).

For night travel with legal overhang (10' rear or less) but greater than 4' rear, a red light or lantern plainly visible for 500 feet is required at the end of load projection.

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