How to read a Colorado oversize permit

CDOT issues oversize/overweight permits online in COOPR, which builds the route for you; for a single-trip permit CDOT says 'Routing is stated on the permit,' listed by highway numbers. Points on a highway are given as RP (reference point) or exit numbers, and your escorts depend on the color of each highway on CDOT's Pilot Escort and Oversize Restriction Map.

How to read the route

CDOT has not published a sample permit, so we can't show where the route prints. Colorado's rules say a single-trip application must give a start and end point in Colorado and the 'Preferred Route(s) of Travel listed by highway numbers.' COOPR then generates the route, and CDOT's permit page says 'Routing is stated on the permit.' Expect highway numbers like I-70, U.S. 285 or SH 82. Locations along a road are given as RP (reference point) or exit numbers.

Road names on Colorado permits

On the permit	Means
I-70	Interstate 70
U.S. 285	U.S. Route 285
SH 82	State Highway 82
RP 258.7	Reference Point 258.7. CDOT defines a reference point as a physical location measured from the preceding milepost marker.
Exit 259, RP 258.7	The Morrison exit on I-70. The exit number (259) and the reference point (258.7) are not the same number.

Where the route starts and ends

Colorado's rules require a start and end point as origin and destination within Colorado on every single-trip and Chapter 6 Special permit application. How COOPR prints them on the permit is not published.

Conditions to watch for

Night travel

Loads up to 12 feet wide may run at night with one flashing yellow light on the front and two or three on the rear. Over 12 up to 14 feet also needs a front pilot car on two-lane highways and a rear one on four-lane highways. Over 14 feet wide can't travel after dark without a Chapter 6 Special permit. Source

“An Extra-legal Vehicle or Load more than fourteen feet in Width is prohibited from travel during Hours of Darkness”

Denver rush hours

Oversize loads can't travel on listed Denver-area segments (parts of I-25, I-70, I-76, I-225, I-270, U.S. 36, U.S. 285, Federal, Sheridan, Kipling, Wadsworth and 6th Avenue) on weekdays from 6 to 9 a.m. and 3 to 6 p.m., unless a Chapter 6 Special or Super Load permit allows it. Colorado Springs, Pueblo and SH 82 between Carbondale and Aspen have their own weekday curfews, 7 to 9 a.m. and 4 to 6 p.m. Source

“during the hours of 6:00 a.m. to 9:00 a.m. and 3:00 p.m. to 6:00 p.m., Monday through Friday”

I-70 mountain corridor

Between the Morrison exit (Exit 259) and West Vail (Exit 173): from December 1 to March 31, no westbound travel Friday 3 to 8 p.m. or Saturday and Sunday 7 a.m. to noon, and no eastbound travel Saturday and Sunday 3 to 9 p.m. From May 15 to September 15, no westbound travel on Friday from 4 p.m. at Morrison (5 p.m. at East Idaho Springs, Exit 241) until 8 p.m., or Saturday 8 a.m. to noon, and no eastbound travel Sunday 3 to 9 p.m. Source

“Westbound Travel Prohibited between 3:00 p.m. and 8:00 p.m. on Fridays”

Holidays

Oversize loads can't travel 6 a.m. to 9 p.m. on Memorial Day, Independence Day and Labor Day, or noon to 9 p.m. on the Friday before Memorial Day and Labor Day. When Independence Day falls on a weekend, the Friday before (Saturday holiday) or the Monday after (Sunday holiday) is also closed noon to 9 p.m. Source

“is prohibited from travel between the hours of 6:00 a.m. to 9:00 p.m. on Memorial Day, Independence Day, and Labor Day”

Pilot cars by map color

In daylight, the pilot cars you need depend on the color of the highway on CDOT's Pilot Escort and Oversize Restriction Map. For example, on a blue highway: over 8'6" up to 11' wide needs one front pilot car; over 11' up to 13' needs front and rear; over 13' needs a Chapter 6 Special permit. Over 16 feet high needs a front pilot car with a height pole. Source

“as designated on the Pilot Escort and Oversize Restriction Map”

Signs

Show 'Wide Load', 'Long Load' or 'Oversize Load' signs (or 'Wide', 'Long', 'Oversize') front and rear. Signs are black on yellow, either 5 feet by 10 inches with 8-inch letters or 7 feet by 18 inches with 10-inch letters. Source

“which shall be visible to approaching traffic from the front and the rear”

Easy to miss

Exit numbers and RP numbers differ. The rules give the Morrison exit on I-70 as 'Exit 259, RP 258.7', so check which one the permit uses before you count mileposts.
Clear Creek Canyon is closed to oversize loads at all times on U.S. 6 between SH 58 (RP 271.6) and SH 119, unless a Chapter 6 Special or Super Load permit allows it.
At the Eisenhower-Johnson Memorial Tunnels on I-70 (mileposts 213-214), loads over 11 feet wide must stop at the tunnel approach parking lot and get permission before going through.

Questions

What are the Denver curfew hours for oversize loads?

6:00 to 9:00 a.m. and 3:00 to 6:00 p.m., Monday through Friday, on the Denver-area segments listed in CDOT's rules. A Chapter 6 Special or Super Load permit can allow travel then.

Can a wide load travel at night in Colorado?

Yes, up to 14 feet wide. Up to 12 feet needs flashing yellow lights front and rear; over 12 up to 14 feet also needs a pilot car (front on two-lane, rear on four-lane). Over 14 feet wide can't travel after dark without a Chapter 6 Special permit.

When can't oversize loads use I-70 in the Colorado mountains?

Between the Morrison exit and West Vail, on winter and summer weekend peaks. In winter (Dec 1 to Mar 31) westbound is closed Friday 3-8 p.m. and Saturday and Sunday 7 a.m. to noon, and eastbound Saturday and Sunday 3-9 p.m. In summer (May 15 to Sep 15) westbound is closed Friday afternoon until 8 p.m. and Saturday 8 a.m. to noon, and eastbound Sunday 3-9 p.m.

Sources

Your permit is the legal document; follow everything it says. Rules change; check CDOT's site before you move.Last checked October 2026.