KINGSTON — When cars queue for ferries in Kingston during busy summer months, locals know to stay clear of downtown.

Four lanes of traffic clog the space between shops and restaurants along the little stretch of Main Street, better known as State Route 104.

“In the summer, forget it, there’s no going down there,” said Dave Wetter, a downtown property owner and Kingston Citizens Advisory Council member.

That could change as Kitsap County resurrects a plan to reroute eastbound SR-104 onto NE East 1st Street, one block north. Bainbridge-based Cascade Design Collaborative is completing preliminary designs to expand 1st Street to four lanes to serve both loading and offloading ferry traffic. That would leave Main Street more open for walkers and local drivers, Cascade Principal Eric Schmidt said Wednesday in a presentation to the Kingston Citizens Advisory Council.

“It allows you to take back the downtown,” Schmidt said.

Some downtown business owners say what’s good for walkers could be bad for business.

The stream of summer ferry traffic gives valuable exposure to Main Street businesses, said Drifters Galley manager Don Cummins. Travelers see the restaurant as they pass through and come back once they’re parked in the ferry holding lane.

“We have our locals in the winter, but that traffic in the summer is our bread and butter,” Cummins said Wednesday. “That’s pretty much why this place is here.”

Just up the street at the Coffee Exchange owner Annemarie Olson agreed.

“If they do that we’re out of here,” she said. “This is a ferry town.”

Kitsap County Public Works Transportation Planner Greg Cioc said he hadn’t heard negative reactions from downtown businesses, but said public outreach for the project has yet to begin.

County officials planned to review the study with Department of Transportation staff this week and will present a refined proposal at a community meeting later this winter, Cioc said.

With public support, the county would seek state and federal money for designs through the Puget Sound Regional Coordinating Council, likely in 2012. A request for construction money could follow in 2015.

“It’s at least that far out,” Cioc said. “And that’s being hopeful.”

The project is already 20 years in the making.

The Department of Transportation began planning the reroute in the early 1990s and several designs were proposed. The most elaborate included ramps and tunnels, Cioc said.

Money for the project was never found and eventually the designs were lost in an office fire. State Route 104 remained saddled on Main Street.

This year the county jumped at the chance to use about $200,000 in unspent grant money to craft preliminary designs for a reroute.

In Cascade Design Collaborative’s preliminary design, East NE 1st Street, currently a two-lane westbound street, would become a four-lane street, with two lanes traveling in each direction. One eastbound lane could be used for parking during slower seasons, Schmidt said.

The ferry toll booths would be moved to the end of 1st Street. Buses, bicycles and emergency vehicles could still use Main Street. Bathrooms and the covered terminal area would remain untouched. Two lanes of Main Street would become parking and sidewalks would be widened to create a boulevard feel.

Cascade designed several options for routing traffic west of the terminal. One calls for traffic lights to allow westbound traffic to flow left onto West Kingston Road and into downtown. Another option would be to build a traffic roundabout on Community Center property, at the corner of 1st Street and Main Street. Each option could be configured to funnel downtown traffic onto Central Avenue and away from Main Street.