Colorado trailer laws and regulations

Colorado quick reference for anyone towing in or through the state:

Key statute: Colorado Revised Statutes, Title 42, Part 2 (CRS 42-4-201 through 42-4-235) covers vehicle equipment and trailer requirements.

Brake threshold and breakaway

Trailers with a gross weight of 3,000 lb or more must have brakes on all wheels, operable from the driver’s seat, with automatic application on breakaway. That’s CRS 42-4-223. The breakaway requirement means a battery-powered breakaway switch and lever, not just a safety chain.

A typical 16 ft tandem-axle utility trailer is right at the 3,000 lb threshold once loaded. Most travel trailers and car haulers blow past it. If you’re towing a single-axle 12 ft cargo trailer with a few hundred pounds of gear, you’re likely under. The number is GVWR (rated capacity), not the actual loaded weight, so check the trailer’s VIN tag.

Stopping standard: when traveling 20 mph on dry, level pavement, the combination must stop within 40 feet using service brakes.

Dimensions and what counts

Combined length is bumper-to-bumper, including any cargo overhang. A typical pickup is 18 to 22 feet. That leaves 48 to 52 feet for the trailer.

Width of 102 inches covers most travel trailers and toy haulers. Anything wider needs an oversize-load permit from Colorado DOT. Mirrors and lights are not counted in the width measurement.

Height of 14 ft 6 in is generous (some states are 13 ft 6 in). Most travel trailers are 11 to 12 feet. Watch for low bridges in older parts of Denver and on county roads in the mountains.

Registration

All trailers must be titled and registered in Colorado, including utility, boat, snowmobile, and RV trailers. You’ll need:

• Secure and Verifiable ID (driver’s license)
• Colorado title or out-of-state title to transfer
• Bill of sale or dealer paperwork
• Proof of Colorado insurance on the tow vehicle (the trailer is covered under the tow vehicle’s liability)

Homemade trailers need extra paperwork:

• Bill of sale for materials, verified by the county motor vehicle office
• DR 2409 (Statement of Homemade Trailer and Assignment Trailer I.D.)
• DR 2704 (Certified VIN Inspection), done by Colorado State Patrol or a county designee

Plates are issued by the county clerk’s motor vehicle office, not the state directly.

Mirrors

Both outside mirrors must show at least 200 feet of roadway behind the vehicle. If your trailer is wider than the tow vehicle, factory mirrors usually won’t cut it. Clip-on tow mirrors, magnetic extensions, or telescoping factory tow mirrors are the common fixes.

A wide-body truck with stock mirrors towing a 102-inch travel trailer is typically not legal without extended mirrors. Most pickups (F-150, Silverado, Ram 1500) offer optional tow mirrors that swing or telescope. If yours doesn’t have them, $50 to $80 clip-ons solve it.

Lighting

At minimum:

• Two red tail lamps on the rear, visible from 500 feet
• Stop lamps activated when the tow vehicle brakes
• Turn signals visible from the front and rear
• License plate light
• Reflectors on the rear (red) and sides (amber front half, red rear half) on trailers over 80 inches wide

Tail lamps must be mounted 20 to 72 inches above the road. Most boat trailers and small utility trailers ship from the factory compliant. Older trailers with corroded grounds are the usual offenders.

If you’re towing a Ford built in 2021 or later (F-150, F-Series Super Duty, Ranger, Expedition, Maverick, Transit 2026, or Lincoln Navigator), check whether your truck has had Ford recall 26C10 / NHTSA 26V104000 applied. The recall covers about 4.3 million vehicles for an Integrated Trailer Module software fault that can disable or randomly trigger trailer lights and brakes. OTA fix pushed March 2026.

Speed and lanes

Colorado has no separate speed limit while towing. Posted limits apply (75 mph on most interstates, 65 to 70 on rural state highways).

CRS does require that a tow vehicle “operate in such a manner that it does not impede the normal and reasonable movement of traffic.” Translation: if your trailer is swaying or you can’t keep up, slow down or move to the right lane. On a six-lane interstate (parts of I-25 and I-70), trucks and combinations over 26,000 lb GCWR must use the two right lanes only.

I-70 west of Denver has chain laws in winter (Traction Law / Passenger Vehicle Chain Law / Code 18) that apply to towing setups too. Have chains or M+S tires when posted.

Safety chains and hitches

Two safety chains, crossed under the tongue to catch the coupler if it lets go. Chains must be rated for the trailer’s gross weight (each chain at least 50 percent of trailer GVWR is the rule of thumb; Class III rated chains are 6,000 lb each).

No specific hitch class requirements in statute, but the hitch must be adequate for the load. A Class II receiver (3,500 lb) towing a 5,000 lb trailer is both unsafe and a citation in a stop.

What gets people ticketed

Colorado State Patrol writes most trailer-related citations for:

• Burned-out tail or brake lights (the cheapest fix, the most common stop)
• No breakaway battery / dead breakaway switch on trailers over 3,000 lb
• Improper or no safety chains
• Expired registration on the trailer (state-issued sticker)
• Mirror visibility on wide combinations

Most stops result in a fix-it ticket if the issue is minor. A non-functional breakaway brake on a 7,000 lb trailer is treated more seriously.