Colorado oversize permit requirements
Colorado is the one state on this corridor where the mountains write the permit rules. The single figure that governs more routes than any other is the Eisenhower Tunnel on I-70, capped at thirteen feet eleven inches — below the legal height of most loads crossing the state, and low enough that a tall load bound for the Western Slope is not taking the Interstate at all.
Night movement is allowed, which is unusual: a load up to twelve feet wide may run in darkness with proper lighting, and between twelve and fourteen feet it may do so with an escort. The permit runs five days. Denver adds a wrinkle — city streets need a separate city permit, and that takes two to three days on its own, so an urban delivery has two clocks running, not one.
The other seasonal rule is the I-70 chain law, in force from the first of September to the end of May between mileposts 133 and 259. That is nine months of the year on the main east–west route. Routine permits run to a hundred and thirty feet of length on four-lane highways and seventeen feet of width; beyond seventeen feet wide, or two hundred thousand pounds gross, the load is a superload and approval takes six to ten days.
Legal dimensions
At or under these figures, no oversize permit is required in Colorado.
- Width
- 8′6″
- Height
- 14′0″
- Gross weight
- 80,000 lb
- Overhang
- 4′ front, 10′ rear
- Steer axle
- 20,000 lb
- Single axle
- 20,000 lb
- Tandem
- 36,000 lb
- Tridem
- 54,000 lb
Routine permit limits
Above legal dimensions and up to these figures, Colorado issues a permit as routine business. Beyond them the load becomes a superload, reviewed case by case.
- Length
- 130′ on four-lane highways
- Width
- 17′
- Height
- 16′ — above 14′6″ a survey is required
- Single axle
- 22,000–27,000 lb
- Tandem
- 42,000–50,000 lb
- Tridem
- 55,000–65,000 lb
- Quad
- 60,000–72,000 lb
Escort requirements
A load reaching any of these figures needs an escort in Colorado — the figure is the first size that requires one, so a load measuring exactly this much already needs it.
- Width
- 15′1″
- Height
- 15′0″
- Length
- 115′1″
When the load may move
Permit validity. Permits are valid for five days.
Operating time. Sunrise to sunset generally. A load up to 12′ wide may travel at night with proper lighting; between 12′ and 14′ wide, night travel requires an escort.
Restricted travel. The Eisenhower Tunnel on I-70 is capped at 13′11″ of height. Denver city streets require a separate city permit, which takes two to three days to process. The I-70 chain law runs from 1 September to 31 May between mileposts 133 and 259.
Worth knowing
- Legal length is 57′4″ for the trailer and load.
- Legal gross weight rises to 85,000 lb off the Interstate.
- A load over 17′ wide or over 200,000 lb gross is a superload, and approval takes six to ten days.
- Denver requires its own city permit for movement on city streets.
Colorado permits, answered
How tall can a load be through the Eisenhower Tunnel?
13′11″. It is the constraint that shapes I-70 routing across Colorado, and it is below the legal height a great many loads run at, so a tall load takes another road entirely.
Can an oversize load travel at night in Colorado?
Yes. Up to 12′ wide with proper lighting; between 12′ and 14′ wide with an escort. That is more permissive than most states on this corridor.
Do I need a separate permit for Denver city streets?
Yes, and it takes two to three days to process on its own. A Denver delivery therefore has two clocks running — the state permit and the city one.
When does the I-70 chain law apply?
From 1 September to 31 May, between mileposts 133 and 259 — nine months of the year on the main east–west route across the state.
What counts as a superload in Colorado?
Over 17′ wide or over 200,000 lb gross. Approval takes six to ten days, so it belongs in the schedule at quoting time rather than at dispatch.
Crossing more than Colorado?
A permit is per state. If the route leaves Colorado, these are the states it most likely enters.
Get a permit quote for Colorado
Enter the load once and the estimator prices every state on the route, flags where an escort is required, and turns the quote into an order.
Price a permit for Colorado →Compiled from published state DOT sources. Regulations change — confirm the current rules before dispatch. Last reviewed 2026-07-30.