Duvall Avenue Northeast, a key commuter route between Renton and Bellevue, finally closed Thursday for a widening project expected to take about a year.

The closure was delayed for several days from June 2 while the contractor obtained one of the permits for the project, a stormwater discharge permit from the state Department of Transportation.

Duvall is closed from north of Sunset Boulevard Northeast at Southeast 107th Street to Southeast 95th Way.

The closure at Southeast 107th Street allows for local access for a short distance to businesses and homes just north of Sunset Boulevard. The city will install a large illuminated sign on Sunset Boulevard, directing shoppers to that retail area.

The suggested detour route to go north and south is Sunset Boulevard or Interstate 405. However, increased traffic is expected on Southeast 148th Street in May Valley and Union Avenue Northeast, as residents and commuters use those streets, too.

All residents in the affected area will have local access to their homes, including on Duvall Avenue, according to city project manager James Wilhoit. Such access points will change as the work progresses, he said.

Wilhoit stressed that no through traffic is allowed on Duvall and there will be “hard closures” at each end of the Duvall closure.

The City of Renton has sent out flyers and held public meetings to describe the closure and access points and assist in planning alternate routes.

“We think it’s going to go well,” said Wilhoit.

The City of Renton also has worked with the Renton School District to determine impacts on bus routes. The closure will not affect bus transportation this school year, according to the district spokesman.

The spokesman, Randy Matheson, said the road closure will have “very little impact” on the district’s bus routes. The district will move two bus stops, actually closer to the students who use them, he said.

The district also won’t alter the start or stop times of any school to accommodate the closure, Matheson said.

A police officer will keep an eye on traffic on Union Avenue Northeast near Sierra Heights Elementary School. Traffic could back up there if Union is heavily used as a detour route.

Despite plenty of warning, detours and signs on Sunset Boulevard, some business owners on Duvall Avenue are still concerned about the impact of the closure on their customers. That’s especially true of customers who come from the north on Duvall. Access from the south on Duvall via Sunset Boulevard is not affected by the closure.

Don Joss, owner of DJ’s Sports Cards for 20 years – including 18 at his current location on Duvall – expects the road closure will affect his drop-in business, mainly those traveling from the north. “It makes me nervous,” he said of the closure.

The closure will make getting to his store “inconvenient” for many customers. Still, like others, he said the new road “will be great” when it’s done.

Darrell Doepke, owner of the Oil Can Henry’s at Sunset and Duvall, estimates that about 20 percent of his business – which provides automotive maintenance services such as oil and filter changes – comes from the north, from such places as Newcastle, Factoria and Bellevue. Like those customers of Don Joss, his customers who live in Renton stop by when headed home from their workplaces to the north.

“Naturally, we are nervous about the intial impact,” said Doepke.

Doepke’s business has been open for about three years, with about three-quarters of his customers coming from within a three-mile radius.

He’s hoping those customers cut off from the north will find another way to his business once “they get over the initial shock of the road closure.” He’s even thinking about expanding his night and weekend hours.

The impact on other business owners depends on their type of business, Doepke said. Customers who buy on impulse or decide to eat out on the spur of the moment may find more convenient locations, he said.

“We all understand that in the long run that this will be an awesome thing for us,” he said. But, that one-year closure is a “big unknown.”

Still he’s optimistic.

“We are going to survive,” he said. The closure may stunt his business growth, but “it’s not going to put us under.”

The project

The $15 million project to widen Duvall Avenue Northeast in the Renton Highlands includes:

• Widen the road to five lanes, including a two-way left-turn lane in the center

• Convert overhead power lines to underground lines in anticipation of added safety during storms and emergencies

• Add a new traffic signal at Duvall Avenue and Northeast 21 Street

• Add new bicycle lanes

• Add new sidewalks

• Add new curbs and gutters