Work to replace the bridge on Benson Road over Interstate 405 should begin in late June or early July, prompting lane closures during non-peak hours for the next 22 months.

The bridge replacement is part of the $83 million Stage 2 I-405 project by the state transportation department to add a lane in each direction on I-405 from State Route 167 and State Route 169.

Integral to the Benson project is the addition of an onramp to I-405 from Talbot Road and an offramp from 405 to Talbot. The offramp is on the west side of Benson Road and the onramp is on the east side of I-405.

Controversy arose when the state transportation department asked the City of Renton to close Benson Road, which would have cut the time to replace the bridge and add the onramp and offramp by half, to 11 months.

However, before a standing-room-only crowd Monday night, the City Council voted unanimously against the closure. Before the vote, representatives from the transportation department and Stage 2 contractor explained the benefits of a shorter timeline. Representatives also had met with council members in committee.

But in letters and oral testimony, residents and business people made it clear the impacts of a full closure of an important corridor to and from downtown Renton outweighed any benefits a shorter construction timeline might provide.

About 15,200 vehicles use that stretch of road daily.

The alternative would have been to take Benson Highway/Talbot Road to Grady Way or to take the steep hill Puget Drive connecting Benson Road and Talbot Road. Those testifying reminded the council about last winter’s snowstorm that made travel on Puget Drive dangerous.

Transportation officials said the detour would add about two minutes to a commute, an assumption that local residents testified simply wasn’t realistic.

Strong opposition to the closure came from Bill Taylor, president of the Renton Chamber of Commerce. He compared the closure of Benson Road to the roughly year-long closure of Duvall Avenue in the Highlands for a major widening project there.

The Duvall closure has left many businesses “hanging on,” he said, because many customers opted not to find an alternative route to the stores.

“Now they would take the 24 months,” Taylor said the business owners would answer if asked today about whether they would go for a shorter Duvall schedule.

Matt Devine, president of the Victoria Park Homeowners Association, said a full closure would “jam up” the alternate routes to Benson Road, including Talbot Road and Puget Drive.

He said the state transportation was “no friend” of Renton, pointing out that his neighborhood has tried for years to get help blocking the noise from State Route 167.

Initially it was thought the council would vote May 18 on the road closure. But the vote came swiftly after council members King Parker and Greg Taylor said they opposed the Benson Road closure.

“There is no way in heck we can close that road,” Parker said.

Stacy Trussler, deputy director of the I-405 project for the transportation department, said in an interview that originally the state proposed the 22-month timeline for the two projects.

But the designer and contractor, a partnership of CH2MHill and Merlino Construction called Corridor Design Builders, wanted to shorten the timeline and use savings to do some of the mitigation work for the project.

The overall cost of the Stage 2 project is $83 million. The cost of the bridge work and the onramp and offramp is lumped together in that big figure.

Trussler said the state had to act quickly to meet the state regulations related to such design/build contracts. A better scenario, she said, would have been to have more time to reach out to residents about the projects and the potential impacts.

“That was an appropriate decision based on what they heard from the community,” she said of the City Council’s vote.

Now the work is expected to begin in late June or early July. Work will halt during peak hours of travel in the morning and evening. Some lane closures are planned and the freeway itself will close when the bridge is torn down.

Work on both projects will finish in 2011.

Benson Road would have closed from City Hall to Eagle Ridge Drive S.

The shorter timeframe also meant the state could complete work sooner on the half-diamond interchange at Talbot Road and I-405. The half-diamond interchange at SR 515 will consist of an off-ramp from southbound I-405 to Talbot Road and an on-ramp to northbound I-405 from Talbot Road.

Project information is available here.