Concrete Soon To Be A Field Of Dreams -- Lid Over I-90 Stretch On Mercer Island To Host Park, Recreation Facilities

MERCER ISLAND - Football and soccer fields, three baseball diamonds, two outdoor basketball courts, four tennis courts that might double as skateboard arenas, a sheltered picnic area, children's play equipment, bicycle and pedestrian trails - all this on 24 acres with a view of the Cascades, the Olympics and the downtown high-rises of both Bellevue and Seattle.

It's a park Mercer Island has been looking forward to for nearly two decades, and now it's about to be built - on top of Interstate 90.

When completed, it probably will be the first example of a recreational park built on top of a freeway anywhere in the world, according to highway officials.

And it will be followed shortly by the second example, a few miles to the west: A smaller complex is scheduled for completion by 1995 in Seattle, where a lid over I-90 extends westward from the Mount Baker tunnel.

The two parks also might be the last to be built atop freeways for some time, at least in the United States, because of funding constraints.

The Mercer Island park will occupy an enormous concrete lid covering a half-mile stretch of I-90 where it cuts around the island's First Hill from 76th Avenue Southeast to West Mercer Way.

After receiving approval from the City Council last week, the city is advertising for bids on the park's first phase, to be completed by early 1994.

The idea of lidding Seattle-area freeways started with attorney Jim Ellis, who said last week he recalls walking across Interstate 5 on Seneca Street in 1967 and thinking, "Gosh, we could stretch this farther over the freeway easy as pie." His friend Dan Evans, an engineer and at that time state governor, enthusiastically agreed, as did Director of Highways George Andrews. Andrews, who died two years ago, also supported the idea of putting a lid over I-90.

Although Seattle's Freeway Park - a passive-recreation facility - didn't open until 1976, the basic design was on the drawing boards by 1970, when Mercer Island began seeking ways to mitigate the effects of a mammoth interstate freeway on the quiet, residential community.

The lid initially was intended to hide the traffic, muffle the noise and reconnect neighborhoods severed in 1940 by Sunset Highway, which I-90 replaced. The concept of adding recreation facilities, in an area of the island where public recreation opportunities are scarce, crept up on I-90 designers.

Ellis, who also fathered the Convention Center over I-5 in Seattle, points out that using freeway air space not only creates new land but "adds value to that land which is greater than the cost of constructing the facility." The idea attracted lots of attention from around the country. "At least a dozen groups came and looked at Freeway Park and went away enthused," Ellis says.

"But they haven't done anything. It takes a confluence of events and persistence by a combination of people to make it happen."

It also takes money - and federal freeway funds have dried up, officials say. Once the long I-90 lids on Mercer Island and in Seattle had been approved in the 1976 environmental-impact statement, they were locked in by a federal-court decision and thus protected against the encroaching government frugality of the 1980s.

Such lids are unlikely to be duplicated anytime soon, anywhere else.

Mercer Island expects to spend about $1 million: approximately half from the 1989 King County open-space bond issue, with the council raising the rest by repackaging existing bonds.

The state Department of Transportation, with 90 percent funding from the federal government, is providing the earth cover and most of the landscaping as part of a $146 million project that includes the roadway, lid structure and the ventilation building and equipment.

The lid complex consumes approximately one-tenth of the cost of the seven-mile freeway.