Metro's new $54 million bus base just north of Seattle roars into service June 8 complete with its own $15 million freeway interchange.

The bus base features 3 acres of underground parking space for 150 buses. There is outside parking space for another 70 buses. It is the most expensive bus base built by Metro, almost as expensive as the Kingdome.

Metro estimates a savings of $417,000 in fuel, maintenance and operation costs in 1991, said Metro spokesman Dan Williams. Most of the buses that will operate out of the north base now are sent back and forth across Lake Washington from a Bellevue base, which is temporarily closing.

To make room for the base, Metro relocated 21 families from 11 duplexes and one single-family dwelling that were either moved or razed, and faced much criticism from neighbors. Metro offered to buy another nine houses near the base. So far, it has purchased five of them, Williams said.

Diane Bradley, a neighbor of the bus barn, is not looking forward to its opening. She put in 12 to 14 years fighting plans to locate it near her home.

"I'm going to have 200 buses who will be attempting to reach freeway speed in my backyard," she said. "It's noisy here, but it's going to be a lot noisier."

A total of 336 drivers will work out of the new base, along with 73 vehicle-maintenance workers and 10 support-staff workers.

It took about a dozen years to finally pin down a site for a bus station nobody else wanted on land formerly used for a landfill.

Before construction could begin, however, 126,000 tons of refuse and 90,000 cubic yards of clean dirt had to be removed from the site, said Metro construction manager John Vaughn.

Metro had an exclusive interchange built at I-5 and North 165th Street that only handles traffic onto and off the base, not only buses but also employee and vendor vehicles. It is only one of two such interchanges operating on the nation's interstate highways, said Bob Sokol, supervisor of operations.

Using private ramps, such vehicles may exit northbound and southbound from I-5, or they can enter I-5 southbound from the bus base. But vehicles must go on a new frontage road and cross North 175th Street, mixing with other traffic, before heading north on I-5.

Despite such measures, he anticipates complaints when the buses start leaving the site.

"In the interests of the community we're trying to be as low-profile as possible. But there's some people that would prefer we're not here," Sokol said.