Woodinville intersection to be redone — in a roundabout way

After years of planning, an unusual Woodinville roundabout project appears to be on track for completion next year at an intersection that's bedeviled officials since before Woodinville was a city.

The City Council approved a key agreement Monday, and construction could start as early as spring.

The project involves installing three of the traffic-slowing devices at what's known as the Hollywood intersection, for the 1912 Hollywood Schoolhouse there, at Northeast 145th Street and the Woodinville-Redmond Road.

It's an odd place, in terms of roads, with streets coming together at skewed angles and none of the traffic lanes lining up like a normal intersection.

"It's about the closest we've ever been to getting this constructed," said Mick Monken, city public-works director.

Ideas for how to fix the intersection date to the 1970s, when the area was part of King County. The last work by the county and the state Department of Transportation was done in the 1980s.

When Woodinville incorporated in 1993, the intersection became a city problem. By 1997, Woodinville was working on possible solutions, but no money was available.

Traditional fixes, such as adding lanes or fiddling with traffic lights, didn't seem to work.

"It's just a poor layout," Monken said.

In 1999, the idea of a roundabout came up. By then, several of the traffic-slowing devices had been installed in the Seattle area. The first roundabouts appeared on the Eastside in the late 1990s and are now in several cities, including Kirkland, Sammamish and Monroe.

After decades of use in Europe, roundabouts began popping up in the United States in the 1990s, with about 110 installed nationwide by 2000, according to the Insurance Institute for Highway Safety.

The concept behind them is fairly straightforward, Monken said. Instead of having long lines of cars come to complete stops at intersections, roundabouts provide a way for vehicles to keep moving, speeding traffic flows.

The Hollywood intersection is particularly troublesome, he added, since drivers are generally moving at the 45-mph speed limit — or faster — when they suddenly have to stop for a traffic light. A roundabout offered a solution but also presented difficulties.

"The problem was that the Washington State Department of Transportation wanted a large roundabout that took too much property from the adjacent property owners," noted Monken in a report to the City Council.

In August 2004, the city hired consultant and roundabout expert David Evans & Associates.

That fall, plans were announced for a $52 million commercial project, to be called Woodinville Village, near the intersection. The development is planned as a mixed-use project, including businesses, condominiums and wineries in a designated tourist-destination area on Woodinville's south edge.

By December 2004, concepts calling for a reduced main roundabout and two smaller approach roundabouts had been developed, and the City Council directed Evans & Associates to prepare a design. At the same time, the Woodinville Village developer, MJR Development, agreed to a partnership on the roundabout project.

The idea behind the three roundabouts is to provide a transition area, Monken's report explains.

"The smaller roundabouts act as slowing devices for traffic before entering the larger, two-lane roundabout," he noted. "The slower approach vehicle speeds allow for the main roundabout to be of a small diameter."

The concept now calls for the two smaller, 125-foot-diameter roundabouts to be to the south and west of the 145-foot-diameter main roundabout. One small roundabout would be in the Woodinville-Redmond Road and the second in Highway 202, or Northeast 145th Street, between the intersection and the Sammamish Slough. The small roundabouts will be in the roadways leading to the intersection but won't be at the intersection itself.

The result is that less right of way is needed and costs are lower, Monken said.

Money also became available for the $4 million project, with MJR agreeing to pay about $1 million and the state Transportation Improvement Board adding $2.1 million. In November, the roundabout project was among 10 the board picked to fund from among more than 400 applications statewide.

The balance of the funds will come from the city. The City Council formally approved an agreement with MJR Monday.

Designs call for two traffic lanes around the main roundabout and single lanes around the two smaller roundabouts.

"The intent is to slow [drivers] to 25 mph," Monken said.

The multiple roundabouts represent a "landmark project" that may be the first of its kind in the nation, he said.

Access to businesses at each corner of the intersection — including the Hollywood Schoolhouse itself, now largely used for weddings and other events — should be vastly improved, he said, with no left-turn lanes.

"All you have to do is turn right," he said.

Monken noted studies that have shown significant drops in accident rates when roundabouts were installed.

Peyton Whitely: 206-464-2259 or pwhitely@seattletimes.com