Building The Sound Barrier Nearly Completed Concrete Wall Along I-90 Giving Residents A Break From The Noise

Good fences may make good neighbors. But it took a concrete wall to make Mona Tobler and her neighbors more sociable.

“Last summer, when we’d sit out in the back yard we could hardly talk,” said Tobler, whose house at W3303 14th is adjacent to Interstate 90.

Tobler and her neighbors aren’t building the 3,053-foot wall between their homes and the interstate. Taxpayers are, at a cost of $458,000.

Designed to deaden some of the noise from cars and trucks struggling up Sunset Hill, the wall is cheaper than buying houses and land adjacent to the interstate, said Al Gilson, spokesman for the state Department of Transportation.

Noise along the north side of I-90 already was close to legal limits when the state began its project to add a lane to westbound lanes.

That new lane put cars and trucks closer to Tobler’s home. But she and her neighbors say the noise is reduced because of the new wall.

“It also looks attractive,” Tracy Cook, W3222 14th, said of the wall that soon will be painted a color transportation officials call “Washington gray.”

“It kind of gives you a safe feeling that the cars are going to stay up there on the freeway.”

The 1,978 feet of wall on the north side of I-90 is nearly complete. It varies in height but averages about 12 feet.

Contractors next year will build a similar 1,075-foot structure on the south side of the interstate.

That wall is needed in part because sound bouncing off the north wall makes life noisier on the south side of I-90, said Gilson.

The wall stops at Finch Arboretum because federal standards are meant to protect residents living, working or attending classes along freeways. They’re not designed to protect people strolling in city parks.

Freeway noise at Woodland Montessori School, on the arboretum grounds, reached 58 decibels when readings were taken in May and June, said Gilson. The federal limit is 67 decibels.

Park caretaker Pam Kriscunas said the readings may have been more startling if engineers had visited in winter, when the park’s 2,000 trees and shrubs were bare.

“The leaves absorb noise,” so the park is noticeably louder in winter, said Kriscunas. “I was hoping the wall would go all the way up (the park’s property line).”

The wall would have deadened sound on the edge of the park nearest the freeway. But sound waves bounce over such structures, so there wouldn’t have been much difference in the majority of the arboretum, said Gilson.

Arboretum staff decided four years ago to build their own sound barrier, a row of fast-growing Serbian spruce and Austrian pines.