Earlier this year, Denver-based engineer consulting firm Mead & Hunt was hired to provide recommendations on what kind of roundabout would be most successful at the intersection of U.S. Highway 6 and Lake Dillon Drive. The move is meant to help slow traffic in the area, support growing car volumes and provide better connectivity for pedestrians, while also providing better access to the proposed Summit County Road 51 workforce housing project.

Those recommendations were officially laid out at the Summit Board of County Commissioners work session meeting Tuesday, Dec. 7. During the meeting, Paul Silberman, department manager of transportation planning, predicted how the intersection and surrounding area could change in the years to come and how these roundabout solutions could mitigate issues with higher traffic volumes in the future.

The proposals:

• The first option is a five-leg roundabout that would have bypass lanes and provide access to Lake Dillon Drive, Evergreen Road, Summit County Road 51 and both directions of U.S. Highway 6.
• The second is a similar roundabout but without bypass lanes.
• The third option is one four-leg roundabout with a second three-leg roundabout at Highway 6 and C.R. 51.
• The last, and cheapest option, is to keep the traffic signal at Highway 6, Lake Dillon Drive and Evergreen Road but construct a three-leg roundabout at Highway 6 and C.R. 51.

Silberman said even with the final option, his firm still recommends the county take up some small projects, such as building out a small median or tightening up the intersection to make it more pedestrian friendly.

The costs:

• The first option is estimated to cost $5.5 million to $6 million, according to Silberman’s presentation.
• The second option — similar to the first without the bypass lanes — is estimated to cost $4.5 million to $5 million.
• The third option with two roundabouts is most expensive and is estimated to cost $7 million to $7.5 million.
• The fourth option is projected to cost $2 million to $2.5 million.

“My opinion as a consultant is, ‘What are you trying to solve out of this project,'” Silberman said. “If it’s a land use, economic development thing, you want your access at the cheapest price possible, and you want to solve the traffic congestion issues associated with the access.”

If that’s the case, Silberman recommended the county do the third option but complete the first roundabout and then, years later, complete the second roundabout when and if it’s needed.

Summit County Commissioner Elisabeth Lawrence said she wasn’t sure how the county could afford the $7 million project, but Summit County Manager Scott Vargo said that even if the county completed some of the preliminary work, such as the designs for the project, it could be drawn out over the course of many years.

“If you do the design work, you at least have that in your back pocket for down the road if you start to see that coming to a challenge,” he said.

Even still, the commissioners previously voiced their preference for the fourth option because of its functionality and because it seemed to be more cost-effective. Vargo said that also initially seemed to be the informal reaction of leaders at the town of Dillon, and Summit County Commissioner Tamara Pogue reiterated that it was still her preference, too.

Later that day, the Dillon Town Council and met to review the same presentation. Dillon Town Manager Nathan Johnson said council preferred the third option, which includes two roundabouts. Both the town and county will share the expense for the project.

Silberman reported that the next steps are to select a preferred roundabout and that his team would complete 50% of the design work. Once that’s done, funding for the project would be identified — including applying for grants — and the Colorado Department of Transportation would need to approve the project.