Colorado Trucking Regulations

Colorado follows the federal 80,000 lbs GVW limit on interstate highways. The Colorado Department of Transportation (CDOT) issues oversize/overweight permits through the Permits Office. Single-trip permits start at $15 for oversize and $30 for overweight — among the most affordable in the nation. Colorado has specific weight restrictions on mountain passes, particularly I-70 through the Eisenhower Tunnel, where certain hazmat loads are prohibited. The tunnel has a height restriction of 13 feet 11 inches. CDOT operates weigh stations at key locations including the Dumont weigh station on I-70 and the Monument Hill station on I-25. Overweight fines in Colorado are calculated by the degree of excess, starting at $50 for the first 1,000 lbs over and escalating significantly for larger overages.

Colorado's chain law (Code 15) is one of the most significant trucking regulations in the state. When CDOT activates the Traction Law on I-70 and other mountain corridors, commercial vehicles must have chains or approved traction devices on drive tires. Colorado issues three levels: Level 1 (Traction Advisory), Level 2 (Traction Law — chains or 4WD required), and Level 3 (Passenger Vehicle Chain Law). CMVs without adequate traction face $500+ fines and can be held liable for closures they cause — drivers who block I-70 due to insufficient traction can be fined $1,131 and held responsible for closure costs. CDOT recommends all CMVs carry chains from September through May for mountain routes. The I-70 corridor between Denver and Vail sees the most chain law activations annually.

Colorado's mountain highways feature mandatory runaway truck ramps on steep grades. The most critical is the I-70 corridor through Floyd Hill, Georgetown, Vail Pass, and Glenwood Canyon. Colorado requires all CMVs to have properly functioning braking systems before descending mountain grades. Following the 2019 I-70 Lakewood crash that killed 4 people, Colorado enacted HB 19-1322, increasing penalties for CMV drivers who cause fatal crashes due to equipment failure on mountain grades. Truck drivers must test brakes before descending steep grades and are required to use lower gears. CDOT provides grade warning signs with recommended speeds for CMVs. Colorado State Patrol actively enforces brake requirements through roadside inspections at mountain weigh stations, particularly during winter months.

Colorado requires emissions testing in the Denver metro area and North Front Range under the AIR (Automobile Inspection and Readjustment) program. Diesel vehicles over 14,000 lbs GVWR are subject to opacity testing in the seven-county Denver metro area. Colorado has adopted clean truck standards modeled after California's Advanced Clean Trucks (ACT) rule, requiring manufacturers to sell increasing percentages of zero-emission trucks starting in 2027. The Colorado Air Quality Control Commission (AQCC) administers these standards. Colorado also has an anti-idling regulation limiting CMV idling to 5 minutes in the Denver metro area (Regulation 16). Carriers operating along the Front Range should plan for emissions compliance and anti-idling enforcement.