Three separate rules get mixed together online: the Traction Law, the Passenger Vehicle Chain Law and the commercial-vehicle chain requirement. Here they are apart.
Traction Law
- When: automatically in effect from September 1 through May 31 on I-70 between Dotsero and Morrison. CDOT can also activate it on other state highways.
- Tires: per CDOT’s 2025 notice, tires need at least 3/16-inch tread and must be winter-rated (mountain-snowflake symbol), all-weather rated or mud-and-snow (M+S) rated. Vehicles that do not meet that must carry chains or an approved alternative traction device (ATD) for two or more drive tires.
- Fine: $50 plus a $17 surcharge for non-compliance, per the same notice.
Passenger Vehicle Chain Law
This is the harsher step. CDOT uses it in severe storms, often before a highway closes. Every vehicle must then have chains or an approved ATD. CDOT says it can be activated on any state highway.
Commercial vehicles
CDOT says commercial vehicles must carry chains or an approved alternative traction device on I-70 between Dotsero (MP 133) and Morrison (MP 259) from September 1 through May 31. Colorado State Patrol’s chain-law page lists additional requirements for commercial vehicles and buses on I-70 west of Morrison to the Utah border. The Traction Law applies to vehicles under 16,001 pounds GVWR or GCWR, per CSP.
Does that include a rental truck or a mover’s box truck? That depends on how the vehicle and trip are classified. We have not verified how it applies to every rental; ask the rental company or mover to state in writing whether they carry chains, and ask CDOT if you drive it yourself.
What it means for the move
- Pick a date with slack. Chain-up delays and closures happen, and a winter move date is a hope, not a promise.
- Ask the mover whether the crew carries chains and has chained up on I-70 before, and what the contract says about delay from weather or closures.
- Do not load the moving day too tightly. A crew that hits a closure may deliver the next day.
- Keep medications, documents, chargers and a change of clothes in your own car.
Eisenhower–Johnson Tunnels
The Eisenhower–Johnson Memorial Tunnels carry I-70 under the Continental Divide at an average elevation near 11,100 feet (FHWA), the highest point on the Interstate system. Secondary sources report a vehicle height limit near 13 feet 11 inches and that placarded hazardous materials are not allowed through the tunnel. We could not verify the current figures on CDOT’s own pages, so confirm height and cargo restrictions with CDOT before sending a tall or loaded vehicle. Ordinary household goods are not hazardous cargo, but ask your mover what it will not take (propane, gasoline, aerosols and similar items are usual refusals) so nothing gets left behind.
Sources: CDOT, new traction law requirements (Nov 2025); Colorado State Patrol, chain law information; FHWA, Interstate 70 fact sheet; live status at COtrip.