An agreement guiding the rehabilitation of a 55-year-old bridge feeding downtown Missoula was approved by members of the City Council on Wednesday, advancing the project for spring construction.
The Montana Department of Transportation plans to begin the year-long rehabilitation of the Higgins Avenue bridge in early 2020 and has placed the cost at roughly $16 million.
The city’s share stands at $1.7 million under the construction agreement approved on Wednesday – up $100,000 from an earlier design. Funding from the city will come from transportation impact fees.
“The overall cost of the project has increased dramatically for MDT,” said Jeremy Keene, director of Missoula Public Works. “They’re only asking us for a small increase in the amount we’re funding, which is primarily to fund the pedestrian elements of the project.”
Keene said the project began as a simple rehab effort, though the city asked for improvements to the pedestrian walkways and other design elements.
The bridge will include four lanes of traffic and wider pedestrian and bike lanes on both sides. The lanes will be separated by a rail from moving traffic.
“This started out as a bridge rehab project, and we asked for some improvements to the pedestrian walkways and other things, which I think will be a dramatic improvement to the bridge,” Keene said.
While the project is set to begin next year, several design elements remain under review. That includes the stairway leading to Caras Park and a plaza planned at Higgins and Third streets, where the bridge terminates on the south side of the river.
“We’re going to take out that slip lane (at Third) and do a nice, wide bulb-out sidewalk that will create a nice pedestrian space there adjacent to the Penwell Building,” Keene said. “We had good suggestions from the public on how the plaza should be designed.”
The current Higgins Avenue bridge was constructed in 1962 and needs major rehab work to extend its life, including structural elements and the deck itself.
MDT will widen the existing bridge piers on dry land to accommodate an additional beam to support a wider bridge deck. Over the river, the deck will be supported by a cantilever system to avoid work in the river.
Two lanes will remain open while half the bridge is renovated, similar to the approach taken on Russell Street, which should be completed when construction starts on Higgins.
Council member Jordan Hess said two lanes is adequate and shouldn’t be disruptive. Roughly 16,000 vehicles cross the bridge each day, the same level as in 1969, he said.
“Traffic on Higgins has not grown in 50 years,” Hess said. “That’s important to keep in perspective. 16,000 cars a day is easily handled by a two-lane system. I think we’re building a little more bridge than we need, but that ship has sailed.”
Keene said MDT plans to bid the project in October, with construction set to begin in late winter or early spring.
“MDT has a tight schedule on this,” Keene said. “They want to keep the project moving along and get it out to bid. We’ve tried to accommodate that and keep it on schedule. We want to keep it rolling.”
Of the four bridges cross the Clark Fork River in Missoula, three will have been rehabilitated or replaced once the Higgins project is complete. MDT finished a $7 million rehab of the Madison Street Bridge in 2017 and is wrapping up new bridge construction on Russell Street.
The department is also replacing the bridge on Interstate 90 over the Blackfoot River just east of the city, and it recently completed two new interchange projects on Van Buren and Orange Street.