State transportation and law enforcement officials in Colorado are introducing new measures aimed at improving safety and reliability along the Interstate 70 Mountain Corridor during winter. The Colorado Department of Transportation (CDOT), Senator Dylan Roberts, and the Colorado State Patrol have announced a left-lane restriction for commercial motor vehicles (CMVs) on several high-risk sections of I-70.
The new rule requires heavy trucks to stay in the right lane unless actively passing, with lane markings and signage now visible at Georgetown Hill, Eisenhower Johnson Memorial Tunnels, Vail Pass, and Glenwood Canyon. This measure is designed to maintain steady traffic flow and reduce crash risks on steep grades affected by winter weather.
CDOT’s winter strategy also includes increased staffing levels across the state, an upgraded fleet of snowplows, improved de-icing technology, and surge deployments focused on I-70. Crews work around the clock during storms to keep roads clear and respond to emergencies quickly.
The left-lane restriction is expected to decrease major incidents that block lanes. According to CDOT, heavy vehicles in the left lane can cause sudden speed changes that result in spinouts, rear-end collisions, and congestion. Keeping these vehicles in the right lane helps prevent secondary crashes and allows snowplows to operate more safely when clearing multiple lanes simultaneously.
“Every minute matters during a winter storm,” said CDOT Executive Director Shoshana Lew. “When a semi blocks the left lane on Vail Pass or the Eisenhower Johnson Memorial Tunnels approach, it can shut down travel for hours. This restriction helps prevent those closures and gives our crews the room they need to keep the corridor open.”
“My constituents along the I-70 corridor and I are thrilled to see these left lane restrictions and prominent warnings go into effect,” said State Senator Dylan Roberts (D-Frisco). “We worked hard, in a bipartisan manner, to pass SB24-100 which put in place these left lane rules, among other measures, which will cut down on unnecessary crashes, spin-outs, and delays for I-70 travelers. This is good, common-sense action by CDOT that will keep people safe and keep our roads open.”
The Colorado State Patrol is enforcing this new regulation at multiple locations including Floyd Hill, Georgetown Hill, Eisenhower Johnson Memorial Tunnels, Vail Pass, Dowd Junction, and Glenwood Canyon. Troopers conduct regular patrols during storms and peak travel times to identify violators; fines and points may be assessed.
“This law, coupled with the expanded chain law, is intended to reduce or prevent traffic delays, closures and devastating crashes,” said Lt. Colonel Joshua Downing of the Colorado State Patrol. “Professional drivers hold responsibility, just like every other driver, to be prepared and courteous when traveling in winter conditions. Together we can keep I-70 moving safely.”
The CMV restriction also supports CDOT’s de-icing strategy by helping anti-icing materials work more effectively due to predictable traffic flow. By directing commercial vehicles into lanes that receive frequent plowing and treatment, officials aim to reduce jackknifes or stalls that could close challenging parts of I-70.
Crews have added road markings indicating where commercial motor vehicles must adhere to left-lane restrictions.
