The existing structure, a single-lane concrete box culvert, was built in the late 1960s during the original construction of I-70. It is currently in poor condition and is functionally obsolete. In order to replace it, work has begun along I-70, approximately 2.6 miles west of the tunnel. Westbound motorists can expect two lanes of traffic from the tunnel to Mile Point 211, to ensure safety and emergency pull-off access for the traveling public.
“In order to prevent major traffic impacts, we’re using a tried-and-true strategy for managing construction projects in this area,” said Regional Transportation Director Michael Goolsby. “By extending two westbound lanes further west from the tunnel and closer to Silverthorne and Exit 205, we’re preventing a bottleneck from developing for westbound traffic. Three uphill eastbound lanes will be maintained throughout the duration of the project.”
When complete, the new underpass will improve the structural integrity of I-70 in that location and ensure safe access for emergency services to motorists, as well as efficient maintenance and plowing operations. The new structure will be widened to 36 feet, which will accommodate two-way traffic and improve the approach turning radius.
The scope for this project includes removal and replacement of the current structure, reconstructing approximately 1,900 feet of the access road, shifting westbound and eastbound I-70 lanes as needed for construction phasing, erosion control, and drainage improvements. Work will continue until fall. There will be a winter shutdown for the project, allowing all six lanes of I-70 traffic to be open, at regular speeds, for the 2021-2022 winter season and heavy ski traffic. Work will resume in spring 2022, and the project is expected to be completed by the end of summer 2022.