Silverthorne pushes CDOT to act on Exit 205 bottleneck, looks for temporary traffic relief

A stretch of westbound Interstate 70 leading up to Exit 205.
Liz Copan /

SILVERTHORNE — In 2010, the Colorado Department of Transportation began a study on Exit 205, the Interstate 70 exit for Silverthorne, Dillon and Keystone. The study was completed in 2011, concluding that a “diverging diamond” interchange would be the most efficient and cost-effective option. This particular type of interchange allows vehicles turning left to move more freely. 

After the study was completed, the project was put on hold when CDOT prioritized the widening of the Twin Tunnels near Idaho Springs. The Exit 205 project was supposed to be picked up again two years later, but nine years later, there still isn’t a clear timeline for when the project would be completed. 

“There’s certainly some level of frustration in our community seeing improvements to other interchanges along the I-70 corridor,” Silverthorne Town Manager Ryan Hyland said.

Hyland explained that there are dangerous conditions associated with the interchange that need to be addressed, including the on- and off-ramps as well as impacts in town. Among the ramp issues Hyland described is the short and steep westbound on-ramp, which makes it difficult for cars to accelerate to interstate speed in time. 

In town, cars line up in the left turn lane to get onto I-70 eastbound to Denver, causing a traffic standstill during busier times. The intersection where cars turn left onto the interstate or go straight under the bridge is a common area for T-bone crashes. Hyland noted that in 2019, there were 12 such accidents at that intersection. 

“A lot of our traffic woes stem from Exit 205,” Assistant Town Manager Mark Leidel said. 

These types of crashes mean it’s important for first responders to be able to travel to that area, something that can be difficult during gridlock, Hyland said.

Hyland, Leidel and Public Works Director Tom Daugherty represented Silverthorne at a meeting with CDOT in November. Representatives from other county municipalities were there, as well. 

Summit County’s other problematic exit, Exit 203 to Frisco and Breckenridge, was studied by CDOT as recently as 2019. In total, the two projects planned for Exits 203 and 205 would cost an estimated $70 million. 

“Obviously, these are huge undertakings that are not currently funded,” Hyland said. “So a big part of the conversation was, ‘What’s the low-hanging fruit? What are some short-term fixes?”

The group discussed temporary solutions to mediate issues associated with the Exit 205 interchange, which included giving people more green-light time to turn onto the eastbound on-ramp by manipulating the traffic lights. 

“CDOT has indicated to us that signal timing through town could address some of the changes that we’ve had in town,” Hyland said. “Everyone’s trying to make that turn into Denver. We’re awaiting CDOT’s effort to time those signals so that we can see some improvement without having to construct an interchange.”

While not a perfect fix, Hyland and Leidel agreed that changing the signal time could alleviate some of the traffic that occurs in town.

“We were pleased that the (CDOT) staff and Director (Shoshana) Lew understood the urgency to implement some of the short-term potential fixes,” Hyland said. “We certainly understand the funding challenges that CDOT has and trying to maintain what we have with their current budget seems to be impossible. New projects are an even harder challenge. We feel like 205 is overdue and now obviously 203 comes into that equation and that’s important, as well.”

While Hyland said getting funding for projects through CDOT is difficult, it’s clearly not impossible — just competitive. 

“I think we’re going to be more vocal moving forward about where this ranks and the need,” Hyland said. “It’s time for CDOT to fund this project.”

Leidel said that while officials are having talks with CDOT, Silverthorne is updating its transportation plan to alleviate traffic in town however possible.

“Traffic certainly has become one of those hot-button issues,” Leidel said. “(Exit) 205 tends to be that bottleneck. We need other alternatives.”

Leidel explained that the town is looking at finding a way to get from one side of the interchange to the other without having to cross through the interchange. 

As for the interchange project, Hyland said the decade-old study will need to be updated before construction can begin. 

“I think the bulk of this work is still valid,” Hyland said, patting a 4.25-inch thick binder containing details of the study and project. “But it will certainly need to be updated.”

Hyland said there is not an update on when the survey will be redone.

A representative from CDOT was not available for comment.

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