Colorado Chain Laws
I-70 Chain Law
All commercial vehicles traveling on I-70 between mile points (MP) 133 (Dotsero exit) and 259 (Morrison exit) from Sept. 1 through May 31 must carry sufficient chains to be in compliance with the Colorado chain law.
The Facts
Why
Chains help commercial vehicles traverse the steep climbs often present in the high county. Without chains, vehicles often become disabled, causing traffic delays and sometimes road closures. For the safety of the traveling public, it's critical to use chains to comply with Colorado's chain law.
Passenger & Smaller Commercial Vehicles
A chain law restriction for vehicles weighing less than 16,001 pounds—including passenger vehicles, crossovers, SUVs and small trucks—can be put into effect in Colorado at any time when weather conditions are severe, primarily on roadways with significant ascending and descending grades.
Find Updates
From Sept. 1 through May 31, use the following chain law resources:
Dial 511 from anywhere in the state for the latest traffic updates
Chain Law Level 1/Code 17:
All single-drive axle combination commercial vehicles must chain all four drive wheels; cables are not permitted as ATDs. All other commercial vehicles must have snow tires or chains. Level 1/Code 17 may be implemented any time there is snow covering any part of the traveled portion of pavement on an ascending grade.
Chain Law Level 2/Code 18:
All commercial vehicles must chain up. Single drive axle combination and tandem drive axle commercial vehicles must chain four drive wheels. Auto transports must comply to the extent possible without causing damage to hydraulic lines. Buses must chain two drive wheels to comply. Level 2/Code 18 may be implemented any time there is snow covering the entire traveled portion of pavement on an ascending grade, or when driving conditions dictate that this level is necessary to protect safety and to minimize road closures.