CDOT and partner agencies celebrate completion of I-70 Auxiliary Lane Frisco to Silverthorne improvements project

Summit County — The Colorado Department of Transportation, elected officials, Federal Highway Administration, Summit County, Town of Frisco and the Town of Silverthorne gathered on Tuesday, Dec. 5, to celebrate the completion of the I-70 Frisco to Silverthorne Aux Lane project. The project serves as an important part of CDOT's 10-Year Plan, and will improve safety along a critical artery for Summit County residents, visitors and through-traffic.

Safety improvements on the project include the addition of the auxiliary lane along approximately three and a half miles of interstate.

“In addition to the new auxiliary lane, this project includes structural work widening two eastbound bridges over the Blue River and US Highway 6 to accommodate the aux lane and generally make this section safer for all travelers,” said CDOT Executive Director Shoshana Lew. “This is anticipated to reduce crashes and help all travelers move around each other in rough weather conditions, whether those folks are freight traffic, single occupancy vehicles, buses or other travelers.”

High crash rates lead to delays for emergency response and can require partial interstate closures. For example, frequent interstate closures during inclement weather at exit 205 can back traffic to the west toward exit 203. Having the auxiliary lane means CDOT can keep at least one lane open or quickly reopen one lane. Project work also included an improved deceleration lane with a safer single lane exit at the eastbound exit 205 off-ramp to Silverthorne and Dillon.

“The new off-ramp layout will provide improved traffic flow, capacity and turning movements to northbound Colorado Highway 9 to Silverthorne and eastbound US 6 to Dillon and Keystone,” said CDOT Region 3 Transportation Director Jason Smith.

“Interstate 70 is a vital link not only for the daily activities of Summit County residents and businesses,” said John Cater, Colorado Division Administrator with the Federal Highway Administration. “It's important for travelers from the Front Range to come up and recreate in the summer and winter as well as freight traffic from beyond Colorado’s borders. Prioritizing this project is critical for this section of the interstate to serve local, state, national needs, and everything in between.”

Contractor Ames Construction and CDOT’s construction management team of Cirque Civil, Inc./RockSol Consulting Group constructed and managed the project, respectively. Work began in the spring of 2022, and CDOT and partner agencies gathered for a groundbreaking.

“I-70 is a critical part of the Western Slope economy, and this project is crucial in strengthening infrastructure that connects us to the Front Range and the rest of the country,” said Speaker of the Colorado House of Representatives Julie McCluskie, House District 13. “I’d like to thank Director Lew and all of the CDOT employees who have worked so hard this summer to deliver on so many of the 10-year plan projects. Now, mountain and rural communities and visitors alike will benefit from a safer and quicker I-70 drive.”

The project is part of a larger series of safety improvements on I-70 in 2022 and 2023. They include improvements to Eisenhower Johnson Memorial Tunnels, resurfacing from Silverthorne to Eisenhower Tunnel, the I-70 Structure Replacement West of Eisenhower Tunnel, and the Eisenhower Tunnel Infrastructure Upgrades. Also underway is the West Vail Pass Auxiliary Lanes project.

“Safety and efficiency along this corridor cannot be overstated. This auxiliary lane and other project safety improvements are already helping with those goals,” said State Senator Dylan Roberts. “It’s been a privilege to support 10-year plan projects with funding from the state legislature, and I hope we can do more moving forward.”

“For Summit County locals, I-70 is the road we take to pick our kids up from school, the route our buses take folks to work and the road our first responders and public safety officials rely on to respond to emergency incidents,” said Summit County Commissioner Tamara Pogue. “This project is incredibly important to Summit County and everyone in our community. I am grateful for so much of the support we’ve received to make this happen.”

“This section of I-70 is not only the road our emergency services use to get around to respond to incidents, we also respond to incidents on this stretch of roadway,” said Ryan Hyland, Chair of the I-70 Coalition and Silverthorne Town Manager. “This third lane will hopefully mean we need to respond less often to crashes on I-70 because it’s safer.” Hyland noted how smoothly the project was managed, despite night work, detours and other challenges.

The project also included drainage improvements and installation of wildlife fencing along both eastbound and westbound I-70.

The scenic area overlooking Lake Dillon had been closed during the project for construction staging and improvements. The overlook was widened for safety improvements, which include additional truck parking and the installation of new street lighting. It reopened in October. Project improvements also include improved signage for the US 6 Loveland pass route. It is important for motorists to easily access the nearby highway, which serves as an alternate route when I-70 is closed near the Eisenhower Tunnel.

The project is part of a larger series of safety improvements on I-70 in 2022 and 2023. Work on the I-70 Floyd Hill project is well underway, as well as the West Vail Pass Auxiliary Lanes project.

Another nearby project in design for improvements is at I-70 exit 203, which is the eastern Frisco exit. Improvements include interchange modifications to help move traffic off I-70 more quickly, especially the westbound off-ramp. The project also includes intersection improvements at the nearby Dillon Dam Road and Lusher Court intersection as well as significant multimodal improvements. The 203 project is on the 10-year plan.

Already completed projects on the I-70 corridor in 2022 and 2023 include improvements to Eisenhower Johnson Memorial Tunnels, resurfacing from Silverthorne to Eisenhower Tunnel, the I-70 Structure Replacement West of Eisenhower Tunnel, and the Eisenhower Tunnel Infrastructure Upgrades.

CDOT also prioritized surface improvements to I-70 east Vail Pass during this construction season. CDOT conducted significant pothole repairs in response to a challenging and snowy winter in 2022-2023, as part of the Polis Administration’s focused effort to address the damage from this past winter. For this effort, CDOT pursued funding for that work as part of a larger effort to resurface roadways hit hard by the previous winter. I-70 and US 40 were key roadways that saw improvements from that effort.

CDOT is committed to multimodal options for travelers along the corridor. This includes CDOT’s bus and shuttle services: Bustang, Snowstang and Pegasus.