$8 million for Tiger Road to AGAPE section nearly certain in CDOT budget; Highway 91 and Silverthorne exchange improvements in planning phase, with an intriguing new design idea that could loosen the traffic knot at the busy junction. Please see the link at end of the story for a full explanation.
By Bob Berwyn
SUMMIT COUNTY — Travelers on Highway 9 in Summit County could soon be zipping along four lanes for the entire distance between Farmer’s Korner and Breckenridge.
Assistant County manager Thad Noll said the Colorado Department of Transportation is only two steps away from securing the $8 million needed to complete the widening of Highway 9 on the heavily traveled route. First, the State Transportation Advisory Committee, meeting Jan. 14, must approve the funds, and Noll said that approval is nearly certain.
“It looks like Region 1 will get the money to do the section from Tiger Road to AGAPE,” Noll said at a meeting of the Summit transit board Wednesday. If all goes as planned, the work should be done by the summer of 2011.
Next week, the state transportation commission will consider how to allocate highway funds for fiscal year 2011, which for CDOT begins July 1, 2010. Noll was confident the Highway project will pass that hurdle as well, which means the project could go out for bid in the summer, with work beginning in late summer or early fall this year, then completed in the spring of the following year.
The section farther south that’s still under construction will be completed this spring and early summer, as soon as conditions allow. Noll also said there’s been some preliminary planning for the more challenging stretch between Farmer’s Korner and Frisco. In parts of that segment, the highway is squeezed between Dillon Reservoir and the mountains, posing some challenges for engineers.
The Tiger Road to AGAPE section will include a new bridge across the Blue River that will enhance aquatic habitat just downstream of a section where the County open space department restored the river running through a section of land that was devastated by dredging. The restored reach provides good habitat for trout, as does the river just downstream of the bridge. The existing bridge forces the water to pass through narrow culverts, which fragments the habitat. The new bridge will be an open-span design, enabling the water to flow freely. The bridge would also provide a river crossing for the Colorado Trail, he said.
Noll said the state transportation agency is also planning for improvements on State Highway 91 from Copper up toward Fremont Pass, including a partial reconstruction of the road and work on the shoulders that would tie into the planning being done for a recpath extension in that corridor.
Finally, Noll said plans for a complete reconstruction of the I-70 interchange in Silverthorne are also progressing with talks about a design that could alleviate the knot of traffic at one of the busiest junctions along I-70.
“There are so many conflicting movements there and the access control is not good. There are just so many things that are substandard,” Noll said, explaining that the left-hand turns for access to I-70 are a problem, as well as the proximity of all the secondary roads providing access to nearby residential and commercial areas.
Planning for the interchange has been in the works for years, but at this stage, Silverthorne officials and the transportation department are looking specific design alternatives, including a ” diverging diamond” traffic flow that might work for that location.
“This new design basically eliminates all left hand turns. it’s phenomenal, Noll said at the transit board meeting. Essentially, the diverging diamond exchange could route traffic off the interstate earlier and eliminate some of the intersections on the secondary road approaches to the interstate. The design has been tried at an exchange in Missouri, where engineers were able to revamp the intersection without spending too much money by using some of the existing bridges.
But the design also requires drivers to learn a tricky move that involves a criss-cross lane switch.
“There are still a lot of issues to look at before reaching a solution, so this may be more of a novelty than the final answer, but it’s good to know that all options are being considered to reduce the conflicts at that location,” Noll said in an e-mail after the transit board meeting.
It’s hard to explain, but NPR did a story about the diverging diamond interchange in Missouri with some excellent animated graphics showing the movement of cars through the interchange. Click here for a link to the story.
Filed under: I-70, Summit County Colorado, transportation Tagged: | Breckenridge, Colorado State Highway 9, Divergent Diamond exchange, Farmer's Korner, highways, I-70, roads, Silverthorne, Summit County government, Summit County News, transportation