The day they had dreaded for more than a decade finally came last week but some residents of Yuma Street NW didn't even know it had passed.

"Did you say the subway is running?" asked Evelyn Morris, who lives in a sturdy brick house on the north side of the street.

"Well, if the noise doesn't get any worse than this," she said, "I reckon we can stand it."

In 1968, when they first learned that Metro planned to bore a tunnel under five blocks of their quiet, tree-lined street, the homeowners of Yuma Street were less placid.

For six years they waged steady warfare, filing four lawsuits, testifying before Congress and jamming three public hearings to express the fear, as one of their leaders put it, that the subway would "vandalize our street and make it unlivable." Subway noise and vibrations would disturb their tranquility, the homeowners said. The air vents, they said, would disfigure their front walks.

As a result of their protests and court victories, the vents were moved from curbs to vacant lots. Otherwise, the tunnel between Connecticut and Wisconsin avenues was built more than 100 feet underground according to Metro's original plan.

Yet, the controversy had substantial impact.

Construction of the subway line to Montgomery County was delayed for more than a year, raising its cost by $6 million. According to Metro officials, the new, more elaborate planning procedures ordered by the U.S. Court of Appeals in the case added about $120 million to the total cost of the transit system.

"It was a tragedy," said Cody Pfanstiehl, former community relations director for Metro who says he met often with residents of Yuma Street for several years. "It's a classic case of people getting scared and not believing our experts. A lot of them are very intelligent people. When they're wrongheaded, they can really delay things."

As Metro officials predicted, noise from the trains has barely been noticed since the Red Line opened Aug. 25 between the Van Ness-UDC and Grosvenor stations. Regular test runs began three weeks before.

"I have not detected any noise , but we just didn't trust them at all," said Joseph J. Saunders, a lawyer who has lived on Yuma Street for 24 years and spearheaded one of the homeowners' main court cases against Metro. "I think Metro had to be taught an expensive lesson, and we had to do it. They have to take citizens' concerns into account.

"They said we were standing in the way of progress," Saunders said. "We felt they were riding roughshod over our rights."

Although Metro encountered unhappy residents at many points along its routes, those in Yuma Street's 73 houses -- all single-family homes now valued between $135,000 and $175,000 -- were unusually able to resist its plans.

The group's first leader, who told Congress in 1969 that the subway would "vandalize" his street and force out its "decent, tranquil middle-class" citizens, was William V. Shannon, then a Washington-based member of the New York Times editorial board and later U.S. ambassador to Ireland. (Shannon now lives in Massachusetts and teaches at Boston University.)

Saunders, who later became chief judge for the Civil Aeronautics Board, was one of three lawyers who volunteered time for the complex cases, preparing hundreds of pages of legal documents. Another case was handled at a reduced pro bono rate by Patricia Roberts Harris (who didn't live on Yuma Street), later a Cabinet officer for President Carter.

The protesters' main scientific expert was Murray Strasberg, a physicist specializing in noise-control problems for the Navy who lives on the street. At the height of the controversy he was president of the Acoustical Society of America, the national organization of sound experts.

Strasberg testified that no matter what Metro did to control them, subway noise and vibration were such "intractable" problems that they would seriously reduce the value of homes nearby. Building a subway "down a quiet residential street is almost obscene," Strasberg said.

Instead, he suggested that the line be run under parks and schoolyards several blocks to the north, a plan Metro rejected because it would have prevented having a station at Tenley Circle.

(Shannon had suggested that the trains run from Connecticut Avenue to Wisconsin Avenue in Maryland because the subway was being built "solely for . . . suburban commuters who have already fled the city.")

Several days after the line opened, Strasberg acknowledged, "I turned out to be wrong. We don't hear it . . . . The fears were genuine. It turns out there was a satisfactory solution."

Strasberg said he knew of no one on the block who has heard the trains. A reporter found three who said they did -- but faintly and not often. "Sometimes it sounds like a plane way overhead," said Miriam Brown, who lives next to an air shaft at the corner of Yuma Street and Reno Road. "But I guess I'm getting immune to it . . . . During construction things were bad."

However, Anne Wallace, who lives next to the vent at 38th and Yuma streets, said it causes no problems at all. In fact, Wallace said she was thinking of holding her wedding next month on the empty lot with the vent grate and shrubs, which Metro maintains as a park. But she said she decided it would be too awkward to ask the transit authority for permission.

Both Strasberg and Metro's experts agree that noise has been reduced by the placement of three-inch thick rubber pads on the floor of Yuma Street's subway tunnel and then "floating" concrete slabs with tracks on top of them. Strasberg said the "floating slabs" would not have been used except for the citizens' protests.

But Vernon Garrett, Metro's director of engineering, said they were installed to meet the authority's own standards for noise abatement and have also been used in many other parts of the subway system.

The Yuma Street residents "just didn't believe what the floating slabs could do," said George P. Wilson, the consulting engineer who designed them. "They forced a lot of restudy and delay and we came out where we started."

Saunders said the Yuma homeowners had such a strong legal case that Metro had not followed proper planning and hearing pocedures that "we could have held this thing up indefinitely or a couple of years more for sure." Instead, he said most agreed to stop legal action in return for a "deal," formalized in a Metro board resolution. Under it Metro promised to buy two private lots for the vent shafts, keep construction trucks and new bus routes off their street, and provide no all-day parking at the Tenley station.

The homeowners' chief foe during most of their battles was Jackson Graham, a former Army major general who was Metro's first general manager. He excoriated the Yuma group as obstructionists.

Later, after retiring to Palm Springs, Calif., Graham headed a homeowners' association there that battled plans for a new highway.

What made him different from the homeowners on Yuma Street?

"I felt they were unreasonable," Graham replied in an interview several years ago. "We were never unreasonable . . . . "

"It's all in the eyes of the beholder," Saunders remarked last week.