The move could force the city to reconsider a formal connection.

Those signs proclaiming “Not A Thru Street” are about to mean business.

Winslow’s most popular traffic bypass – the illegal but unenforced parking-lot shortcut from Ericksen Avenue to Hildebrand Lane, used by hundreds of motorists each day – will be blockaded by property owners on or around April 5.

Traffic bollards or some other prohibitive fixtures will be installed between the 901 Hildebrand building, owned by the Joshua Green Corporation of Seattle, and the 911 building, owned by Bainbridge-based Bamcorp, Green company officials announced this week.

The move will allow tenants and customers to reach the building parking areas, but will prevent cut-throughs between the streets at either end, said Helen Wattley-Ames, property manager for Joshua Green.

Wattley-Ames said her company has grown concerned over the increasing traffic volume through the parking lot; concerns increased recently when a commercial truck driver cutting through the lot took the corner badly and got the vehicle caught on a building downspout.

“What we’re trying to do is take care of our property,” she said. “We’re not trying to force anyone to do anything. We’re just trying to control the traffic on our private property.

“It’s really gotten out of control, to the point that we’re concerned about safety and damage to our buildings.”

Joshua Green Corporation purchased the 901 Hildebrand building, which houses Frontier Bank and Charlie Michaels salon, the 1050 Hildebrand building with Silver Screen Video, and the larger Village Shopping Center, about three years ago.

Wattley-Ames cited a 2001 traffic study that showed some 300 vehicles cut between the 901 and 911 buildings during the 4-6 p.m. peak traffic period. When she visited the property this past November, she said, she counted 30 vehicles cutting through in five minutes.

“If you extrapolate from that, it would suggest that the volume has basically doubled,” she said.

New signage is planned to announce the change to motorists who’ve used the parking lot as a way to come and go from downtown while avoiding the highway or the roundabout route over to Madison Avenue.

“Customers of the two buildings will still be able to approach from the Hildebrand or Ericksen side, and will still have access to parking lots,” Wattley-Ames said. “What we’re doing is cutting off the transit between the two parking lots.”

Joshua Green Corporation notified the city of the decision late this week; public works officials included the notice in their weekly traffic update, then shrugged.

“It’s private property, and they can close it if they wish,” said Randy Witt, public works director.

Still, Witt acknowledged that the change could prompt renewed discussion of a long-proposed formal connection between Ericksen and Hildebrand.

City engineers and others have called periodically for the opening to make a north-south corridor between Winslow Way and High School Road. Several years ago, fire officials wanted to make a formal Ericksen-Hildebrand connection a prerequisite for further development in the area.

But the connection has been opposed by neighbors for more than a decade; concerns have included increasing traffic on Ericksen, and preservation of the grassy pocket park between the two streets.

Opponents several years ago produced a long-forgotten 1991 city ordinance specifying that the Hildebrand-Ericksen “plug” was to be preserved as a park, although it was unclear whether the land was ever actually deeded to the city.

More recently, the city conditioned any further study of a formal Hildebrand-Ericksen connection on changes in traffic volumes and other “triggers.” But an island-wide transportation study, adopted in a split vote by the City Council earlier this year, changes that trigger from the scientific to the political; the street opening is to be revisited only “at such time as the City Council requests the issue to be reconsidered,” the study’s executive summary states.

Even so, Witt said that once the parking lot is blocked and motorists settle into their new patterns, his department likely will undertake some traffic counts to gauge the impact of the closure on nearby streets.

“I don’t think we ever analyzed if it were closed, what would happen,” he said.

Collette Arcand, owner of Charlie Michaels hair salon for the past 11 years, said Friday she welcomes the change. Even with recent development in the Hildebrand corridor, she said, the city has been content to let motorists go through the private parking lot rather than confronting the traffic issue.

The politics, she said, date to a time years ago when the council had several members who lived on Ericksen and didn’t want to see the connection opened.

“I’ve watched (parking lot traffic) grow over the years, and I’ve seen a lot of close calls,” she said, a problem reflected in the difficulties of elderly patrons coming and going from a physical therapist in the neighboring building,

“People don’t even slow down for them, they zip around them,” she said. “It’s a speedway here.”