Travelers heading into Colorado’s high country this spring will once again see construction activity on West Vail Pass – but this time, it marks the beginning of the end.
Starting Monday, April 20, crews return for the final construction season of the I-70 West Vail Pass Auxiliary Lanes Project, a multi-year effort to improve safety and travel reliability along one of the state’s most important mountain corridors. Since construction began in 2021, the project has transformed a 10-mile stretch of I-70 between East Vail and the Vail Pass Rest Area, with the goal of reducing crashes, minimizing closures and making travel through the corridor more predictable year-round.
As the project enters its final phase, work in 2026 will focus on completing the remaining roadway improvements, finishing wildlife crossings, and finalizing a first-of-its-kind avalanche and rockfall mitigation system. Crews will also wrap up paving operations, complete landscaping and make final enhancements to the recreation path that runs beneath the newly constructed bridges.
Some of the most significant safety features are nearing completion this year. Six wildlife underpasses – designed for animals ranging from deer and elk to smaller species – are being finalized west of Vail Pass, along with five miles of wildlife fencing to help guide animals safely beneath the interstate. Together, these improvements are expected to reduce wildlife-vehicle collisions while preserving critical migration routes.
Meanwhile, in an area known as “The Narrows” (near MP 186), crews are continuing to work on an innovative avalanche and rockfall mitigation system. This new infrastructure will allow transportation and avalanche experts to better monitor and manage a known slide path, reducing the likelihood of extended interstate closures during winter months. Completing this work requires highly specialized operations, including rock scaling and helicopter transport, which will result in periodic traffic holds throughout the summer.
Motorists can expect intermittent lane closures beginning in late April, followed by a traffic shift in May that will move vehicles into a head-to-head, barrier-separated alignment. Daytime traffic holds of up to 20 minutes are anticipated during rock scaling operations in early June, with occasional holds continuing into the summer as helicopter work takes place. While most delays will be brief, they may last longer as traffic queues are cleared, particularly during busy travel periods. Night work is also expected to increase as the season progresses.
Despite the construction activity, the Vail Pass Recreation Path will remain open throughout the season. Trail users may encounter brief holds or variable conditions in active work zones, especially early in the spring, but no extended closures are planned.
Much of the project’s impact is already visible to travelers. Drivers are now using a new 2.7-mile eastbound auxiliary lane that helps separate slower-moving commercial motor vehicles from passenger traffic, improving traffic flow on steep grades. Two new bridges, built with a 100-year lifespan and improved alignment, are also in place. Additional upgrades completed in recent years include drainage improvements to better protect Gore Creek, reconstruction of sections of the recreation path, and installation of fiber-optic infrastructure to support real-time traveler information.
Stay Informed
To help motorists navigate construction and changing conditions, transportation officials are encouraging travelers to “know before you go:”
- Checking road conditions, weather forecasts and travel alerts at COtrip.org and the COtrip Planner app provide real-time updates,
- Sign up for project text alerts by texting “vailpass” to 21000 to receive timely notifications about major impacts along the corridor.