Boise’s Gowen Road Bridge will be closed until December over safety concerns
A bridge over railroad tracks in Southeast Boise that was expected to remain partially open during a construction project now will be closed through December, according to the Ada County Highway District.
The Gowen Road Bridge, which passes over the Union Pacific railroad tracks just east of Interstate 84, was temporarily closed earlier this month as work crews began replacing the existing bridge. A long-term project at the site will widen Gowen Road between Exchange Street and Eisenman Road to four lanes, and add new sidewalk and a buffered bike lane, according to an ACHD news release.
But on Tuesday, ACHD announced that after a “temporary shoring was put in place to facilitate the bridge construction,” engineers determined that “the existing embankment could not adequately or safely be shored and could pose safety concerns.”
The “embankment” refers to ramps on either side of the bridge that incoming traffic uses to get over the railroad tracks, according to Shandy Lam, a spokesperson for ACHD. Crews initially drove “long metal pins” into the embankment under tension in an effort “to pull the embankment material together,” Lam said in an email.
Though the bridge itself is not unsafe, Lam said, “the embankment material is not sound enough to hold tension on the pins and thus has a tendency to slough off,” making it unsafe.
Instead of leaving one lane open to traffic, the bridge will be entirely closed until after it is replaced.
“Our intent was to allow for commuters to use one lane of the bridge during the project,” ACHD Engineer Dale Kuperus said in a Tuesday release. “But a full closure will be necessary to complete the project and protect travelers. We understand this poses an inconvenience for commuters in the coming months, however we are happy to report that the closure will speed up the timeline for the project as a whole.”
The project was initially slated to be completed by March 2022, Lam said.
A detour that has been in place this month will remain until the bridge is finished, and Lam said ACHD recommends commuters navigate northwest to South Orchard Street.
