South Bridge: The Glenwood Springs evacuation route everyone wants, but no one can afford — yet
Glenwood Springs City Engineer says design nearly final, but more changes could come
After more than a decade of planning, Glenwood Springs’ ambitious South Bridge Project is on the edge of becoming a reality.
With the design phase past the 90% completion milestone, City Engineer Terri Partch said recently the design could be complete as early as spring, with a final reevaluation of the plan’s environmental assessment scheduled for January.
The public will have an opportunity to weigh in on the project’s scope and potential impact on the Municipal Airport on Jan. 19 at the Community Center, 100 Wulfsohn Road. City staff are still working out the meeting details, but residents can save the date, said Bryana Starbuck, Glenwood Springs public information officer.
In February, the city intends to begin the process of acquiring numerous rights of way for the bridge, which could take up to 18 months.
Yet, funding for the approximately $58.1 million evacuation corridor is still in the air. The city has about $20 million in bonding capacity for the project, the Roaring Fork Transportation Authority has committed $4 million for right-of-way acquisition, and Sen. John Hickenlooper’s office has earmarked about $1 million for the bridge in federal appropriations bills, but the city is still seeking about $38 million for the project, Starbuck said in an email.
If funded, Partch said, the city could start seeking project bids in 2024.
“This is a very ambitious project, especially for a community this size,” she said. “But we also believe it’s paramount to the safety of the community if and when another natural disaster should threaten the valley.”
Traffic throughout the Glenwood Springs area can be likened to stacking dominoes; if one intersection fails, it can impact traffic for blocks — and at times — miles around.
While traffic jams are an inconvenience on any given day, they can become deadly in the event of a natural disaster, such as the Coal Seam Fire in 2002.
“During the Coal Seam Fire, they had to evacuate people out of north and south Glenwood,” Partch said. “They found that people got stuck on the road, because there were too many moving through. They realized people would be trapped in a wildfire event.”
Five years later, Denver-based Jacobs Engineering Group conducted the first environmental assessment for the project in 2007, setting in motion a yearslong effort to create an evacuation corridor for south Glenwood Springs.
A South Bridge is not the only option for evacuation, Partch said, but it is likely the option that could save the most lives.
“I did some wildfire modeling for the FEMA grant we applied for,” Partch said. “I did three different scenarios of a wildfire starting in the 4-Mile Road area.”
Using data from three of Colorado’s largest wildfires, all of which took place in 2020, Partch created scenarios with fire-expansion rates mirroring those historic events.
“In two of the scenarios, everyone gets out if we have a South Bridge,” she said. “In one, the fire-expansion rate was so extreme, that not even South Bridge would facilitate a full evacuation. There would be some lives lost.”
Without South Bridge, the options for evacuating southern Glenwood Springs and the communities of 3-Mile Road and 4-Mile Road entail sending people south on 4-Mile Road to County Road 125/Dry Park Road, an unpaved road with some sharp turns that cuts across open fields and provides little protection from a rapidly moving wildfire before connecting to County Road 108, which feeds into Carbondale.
“Dry Park is very susceptible to fire as well,” Partch said. “In our worst-case fire evacuation scenarios, we anticipated losing the ability to access Dry Park Road.”
Even if the road could be accessed, it could quickly become a chokepoint. Partch said traffic could come to a halt if a large vehicle, such as a semi-truck or Greyhound bus, were to get stuck in one of the road’s sharp turns during an evacuation scenario.
The South Bridge project area begins at the 4-Mile Road-South Midland Avenue roundabout and runs east along Airport Road, dipping under the Municipal Airport runway before going over the Roaring Fork River and connecting with Colorado Highway 82.
Featuring more than a mile of new and rebuilt roadways, the project includes entry points for Holy Cross Energy, Jackson Ranch, County Road 163 and a paved connection to Sky Ranch Drive.
“The evacuation route could serve about 1,700 city residents and an additional 1,300 Garfield County residents,” Partch said.
Airport Road, the project’s primary thoroughfare, is currently used by about 500 vehicles a day. According to traffic studies conducted as part of the project’s design phase, Partch said Airport Road traffic could increase up to about 8,500 a day with potential for a peak of about 14,000 users on high traffic days in a 20-year traffic growth scenario.
As a result of the increased traffic, city staff included a number of “traffic calming” features, such as a roundabout at Morgan Street designed with through-truck traffic in mind and a number of median features separating inbound and outbound traffic. A recent environmental analysis also identified the need for a sound barrier between the Cardiff Glen community and Airport Road.
The right-of-way acquisition process includes 22 temporary easements and 17 permanent easements for a total of 49 acquisitions needed. Partch explained that an easement grants the city permission to use a portion of property without needing to own it outright.
The bridge itself is slated to be 540 feet long and about 58 feet above the ordinary high-water mark, with two lanes and built to accommodate heavy truck traffic.
As the intersection Airport Road would connect with Colorado Highway 82, the Colorado Department of Transportation requested the city widen the highway by about 24 feet to accommodate two northbound turning lanes, which would feed into the project.
One of the biggest hurdles to completing the project is the municipal airport’s runway. A failed tax question in November asked residents to foot the bill for a tunnel under the runway, and some City Council members said without the taxes, the runway could be cut short, rendering it nearly useless, airport users said.
Partch said her team is currently designing the bridge with a tunnel in mind, but conversations are ongoing about extending the north end of the runway to compensate for shortening the south end. Runway options are slated to be a key topic at the Jan. 19 public input meeting, Starbuck said.
As wildfires worsen across the country, the need for evacuation routes grows across Colorado’s mountain communities. For Partch, completing the South Bridge Project could be the crowning achievement of her engineering career.
“Every project we work on serves the community,” Partch said. “But this is one of the most important, because I believe this is a project that could save lives.”