Nov. 4--HILLSBORO -- Emily Knupp thought it sounded like a nightmare -- the idea of closing certain interchanges along Oregon 217 during rush hour.

"Washington Square is there," the Hillsboro resident said. "Can you imagine that at Christmastime?"

Knupp was among 55 people at Monday's Washington County Public Affairs Forum, where Jason Tell, Region 1 manager for the Oregon Department of Transportation, mentioned the possibility of closing on- and off-ramps along Oregon 217 in order to improve traffic flow.

The idea has been kicking around for months, but local elected officials will consider it more carefully at a meeting with state officials Nov. 18. They will try to come up with options for further study and public consideration. Or they may decide it just won't work, Tell said.

Oregon 217 is one of the trickiest corridors in the region because it has so many access points so close together, he said.

Dolores Raymond said the congestion can be horrendous: "It takes me as long to get from my house in Aloha to I-5 (via Oregon 217) as it does to get the rest of the way to Salem."

But the simplest solution is too expensive, Tell said: "We don't have $1 billion to widen all of 217."

Last spring, local and state officials used federal money to contract with DKS Associates to study the issue. DKS is using sophisticated models to predict how traffic would decrease on Oregon 217 and increase on side streets in different scenarios for interchange closures between 4 and 6 p.m.

Preliminary results show a range of effects from 12 different ramp-closure patterns. With no public improvement of side streets, the closure of all interchanges except Southwest Scholls Ferry Road would cut congestion on Oregon 217 by 41 percent, but increase side street traffic by 25 percent.

Leaving open only Scholls Ferry, 99W and the Oregon 10/Oregon 8 exchange would cut Oregon 217 congestion 15 percent but increase it 12 percent on side streets. Closing just the interchanges at Southwest Wilshire Street (Cedar Hills), Allen Boulevard, Denney Road and Hall Boulevard would cut congestion 10 percent while increasing it 5 percent on side streets.

Those numbers will change -- particularly the increased traffic on alternate routes -- when improvements to streets such as Southwest Hall Boulevard or Scholls Ferry Road are factored into the models, Tell said. Improvements such as adding or extending lanes or re-timing signals could ease congestion on those roads, Tell said.

DKS is continuing to refine the study with such new factors.

Improving side streets would cost far less than widening Oregon 217, said County Chair Tom Brian last month.

"We all use 217 for a local street," Brian said. "It was not meant for this, but we don't have good north-south routes in the county."

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