Colorado Truck Lane Restrictions
Colorado's truck rule is a mountain-corridor rule, not a statewide one. On the steep, high-risk stretches of I-70, a commercial vehicle at 16,001 pounds or more can't run the far-left lane except to pass a slower vehicle (C.R.S. 42-4-1014). It's signed and lane-marked across six segments: Glenwood Canyon, Dowd Junction, Vail Pass, the Eisenhower-Johnson Tunnel, Georgetown Hill, and Floyd Hill. State Patrol started enforcing in December 2025. It's a class A traffic infraction, about $100 and four points. Off I-70, only the general passing-lane rule applies, and that one's for everyone.
Which lanes a truck can use in Colorado
Colorado's truck rule is a mountain-corridor rule, not a statewide one. On the steep, high-risk stretches of I-70, a commercial vehicle at 16,001 pounds or more can't run the far-left lane except to pass a slower vehicle (C.R.S. 42-4-1014). It's signed and lane-marked across six segments: Glenwood Canyon, Dowd Junction, Vail Pass, the Eisenhower-Johnson Tunnel, Georgetown Hill, and Floyd Hill. State Patrol started enforcing in December 2025. It's a class A traffic infraction, about $100 and four points. Off I-70, only the general passing-lane rule applies, and that one's for everyone.
Roads, exceptions, and signs
- Where it applies: I-70 mountain corridor only. Six segments by milepost: Glenwood Canyon (MP 115.5-131.0), Dowd Junction (169.5-173.0), Vail Pass (180.0-190.5), Eisenhower-Johnson Tunnel (205.5-221.0), Georgetown Hill (224.0-228.5), and Floyd Hill (243.0-247.0).
- Posted. New left-lane signs and lane markings are up at all six segments. Colorado State Patrol began active enforcement in December 2025.
- General rule: C.R.S. 42-4-1013 — on highways posted 65 mph or higher the left lane is for passing only (all vehicles); plus C.R.S. 42-4-1011 drive-on-the-right.
- Created by SB24-100 (2024); enforcement started December 2025. This is Colorado's only truck-specific lane restriction and it is confined to the six named I-70 segments. 'Commercial vehicle' = 16,001+ lbs GVWR/GCWR used in commerce (C.R.S. 42-4-235 definition).
What a lane violation costs
Class A traffic infraction. About $100 fine plus 4 points against the driver's license.
Colorado Truck Lane FAQ
Can a truck drive in the left lane in Colorado?
Is there a truck lane restriction in Colorado?
What is the fine for a lane violation in Colorado?
Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://law.justia.com/codes/colorado/title-42/regulation-of-vehicles-and-traffic/article-4/part-10/section-42-4-1014/. See our Terms & Disclaimer.
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