Colorado Trucking Regulations

Colorado's freight network must navigate the Rocky Mountains, creating operational challenges unlike most other states. I-70 through the mountains is the critical east-west corridor connecting Denver to Utah, passing through Eisenhower/Johnson Tunnel at over 11,000 feet elevation and descending Vail Pass and Glenwood Canyon. CDOT enforces chain laws and traction laws on mountain passes during winter, and commercial vehicle drivers must carry chains or adequate traction devices when required. Denver is the state's primary distribution hub, with significant growth in the I-25 corridor from Fort Collins to Pueblo. The Colorado Department of Revenue handles IRP and IFTA credentialing, while CDOT manages the permit system for oversize/overweight loads. Energy sector freight — oil, natural gas equipment, and wind turbine components — is a significant segment in eastern and western Colorado.

Trucking authority and registration

  • Authority: Colorado Department of Revenue — Division of Motor Vehicles (IRP/IFTA)
  • IRP jurisdiction: Yes (https://cdor.colorado.gov/motor-vehicle/irp)
  • IFTA jurisdiction: Yes (https://cdor.colorado.gov/motor-vehicle/international-fuel-tax-agreement)
  • DOT permit required: Yes — Colorado requires intrastate carriers to obtain a Colorado-specific authorization number. Interstate carriers with USDOT registration must also comply with Colorado weigh station and permit requirements.

Weight limits

GVWR80,000 lbs federal interstate standard
Single axle20,000 lbs
Tandem axle34,000 lbs

Colorado allows certain agricultural and energy-sector vehicles to operate at higher weights on state highways by permit. CDOT issues overweight permits; some mountain route segments have lower posted limits due to infrastructure constraints.

Notable regulations

  • Colorado's Traction Law and Chain Law on I-70: when activated, commercial vehicles must have adequate traction devices (tires or chains). The Chain Law (requiring chains on all drive and trailer axles) is mandatory during severe conditions and violations carry significant fines.
  • Commercial vehicles over 26,000 lbs GVWR are prohibited from using the left lane on I-70 between Morrison and Dotsero (mountain corridor) — this is a fixed Colorado law, not a weather-dependent restriction.
  • CDOT's CTMS (Commercial Transport Management System) administers oversize/overweight permits; super-load permits may require engineering review and CDOT-approved route surveys.
  • Vail Pass and Eisenhower Tunnel have specific commercial vehicle weight and speed restrictions; carriers should check CDOT's COtrip system before mountain corridor movements.
  • Colorado has a Commercial Vehicle Weight Distance Tax (CVWDT) for commercial vehicles over 26,000 lbs — carriers operating in Colorado must file and pay this tax quarterly with the Colorado Department of Revenue.

State trucking association: Colorado Motor Carriers Association

Frequently asked questions

When is Colorado's chain law in effect on I-70?

Colorado's Chain Law is activated by CDOT during severe winter conditions on I-70 and other mountain highways. When in effect, all commercial vehicles must have chains installed on drive axles and rear trailer axles. The Traction Law (requiring adequate traction devices) applies under less severe but still hazardous conditions. Both are communicated via CDOT's COtrip system and dynamic message signs.

What is the commercial vehicle left-lane restriction on I-70?

Colorado law prohibits commercial vehicles over 26,000 lbs GVWR from using the left lane on I-70 between Morrison (MP 259) and Dotsero (MP 133). This applies year-round regardless of traffic or weather conditions and is enforced by Colorado State Patrol.

What is the Colorado Commercial Vehicle Weight Distance Tax?

Colorado assesses a Weight Distance Tax (WDT) on commercial vehicles over 26,000 lbs based on the number of miles traveled in Colorado and the vehicle's licensed weight. Returns are filed quarterly with the Colorado Department of Revenue. Carriers must maintain mileage records by vehicle and fuel purchase records to support WDT filings.

How do I get an oversize permit for mountain route movements in Colorado?

CDOT issues oversize/overweight permits through its CTMS online portal. Mountain corridor movements on I-70 are subject to additional restrictions on load dimensions, time of movement (often no night moves), and may require escort vehicles. Super-loads require route engineering review.

Sources

Verified 2026-05-26.