Work to replace a bridge on Allen Road over Sandy Creek northeast of Hillsboro is scheduled to begin Wednesday, May 29, Jefferson County Public Works Director Jason Jonas said.
Allen Road runs between Sandy Church Road to the south and Rice Road to the north, and the section of Allen Road that includes the bridge will be closed to traffic when construction starts, Jonas said.
The bridge replacement project is expected to be finished by September, he said.
Gershenson Construction Co. in Eureka is the contractor on the project, which will cost an estimated $1,052,220, he said.
Jonas said 80 percent of the cost will be covered with federal funds, and the county will pay for the rest with its share of a 1/2 cent countywide sales tax for road and bridge improvements.
Jonas said all emergency service and essential service providers have been notified about the upcoming road closure.
Jonas said signs showing an alternative route will be set up on Allen Road, adding that about 200 cars use the road per day.
“It will be fairly easy for folks to see what detour they should take,” Jonas said. “Since (the bridge) is kind of in the middle of Allen Road, you don’t get many people who have to go the full stretch of it. They live on one end or another.”
Jonas said the bridge needed to be replaced. It was built in the 1960s and currently can hold 20 tons. Bridges today are built to hold a minimum of 60 tons.
“For minor creek crossings, it gets to where those old steel bridges will rot out usually from salt trucks treating the roads,” Jonas said. “That salt will meet steel, and it’s done quite a number on the webbing of the steel.”
When a bridge reaches its “danger zone,” or load-bearing capacity of 10 tons, ambulances, firetrucks, trash trucks or school buses will be unable to use it, he said.
“We like to replace these types of old structures before you get to that danger zone causing people unneeded and not welcomed rerouting of emergency services,” Jonas said. “When (bridges) start getting rated below 40 tons, we start putting them on the watch list, and then when they’re under 30 tons, we start programming for replacement. We try to get them fully replaced before or when they’re at 20 tons because we don’t want them to get to 10.”
For a full list of bridges in the county slated for replacement, visit jeffcomo.org/160/Projects.