DOT marking identification - Colorado

The Colorado Department of Public Safety has adopted 390.21 of the Federal Motor Carrier Safety Regulations (FMCSRs), as in effect on October 1, 2025.

Section 390.21 applies to a self-propelled or towed vehicle bearing an apportioned plate or having a manufacturer’s gross vehicle weight rating or gross combination rating of at least 16,001 pounds. Section 390.21 also applies to a vehicle used on a public highway to transport a placardable amount of hazardous materials.

Exception: Combination vehicles with a GVWR or GCWR of 16,001 pounds or more, but not in excess of 26,000 pounds, and not transporting placarded hazardous materials, may meet the requirements of 390.21 by marking the trailer or secondary unit if the power unit GVWR is less than 16,001 pounds.

Exception: Repossessors as defined in 42-6-146(4), CRS are not subject to the marking requirements in 390.21.

The US DOT number must have the suffix “CO” if the carrier is an intrastate only carrier.

Example: USDOT 123456 CO