Isobel A. Warren and Joe Harris have watched the expansion of the Metro subway system from divergent vantage points.

Warren, a Montgomery County resident, sold her car when Metro's Grosvenor station opened in 1984 and now commutes to work by subway.

"I'm really excited about this Metro," she said. "It's super."

Harris lives in Southeast Washington's Congress Heights neighborhood, which has gone without rail service because the Green Line has not opened.

"It's a shame we don't have it," he said. "For me, it would be ideal. The subway's the fastest for getting to work."

Warren, a salesperson who works in Friendship Heights, and Harris, a federal employe who works in Crystal City, are similar to thousands of commuters.

Some have benefited from the subway. Others, including those who live near the Green Line's long-debated route, have not.

A few days before the Grosvenor station opened in August 1984, Warren sold her 10-year-old car for $1,000.

Now Warren walks from her apartment on Rockville Pike north of the Capital Beltway to the nearby Red Line station. She takes an eight-minute subway ride to work.

"I find it much more relaxing," she said. "I pity the people who drive."

She gets some daily exercise by walking up the escalators at the Friendship Heights station. When it snows, she no longer has to worry about traffic snarls.

Soon she will be able to visit her daughter, who plans to move to Gaithersburg, by riding the subway to the nearby Shady Grove station.

Harris' options are more complex.

If he drives to work, he has to pay a high parking fee and his wife must do without a car. Instead, his wife can drive him to the L'Enfant Plaza station, where he can catch a Yellow Line subway. The drive can take up to 30 minutes. Otherwise, he can go by bus and pay a second fare to transfer to the subway.

If the Green Line had opened, Harris said, he could walk from his home to the Congress Heights station and ride to work by subway.

"It shouldn't take over 35 minutes," he added. Under Metro's current plan, the Congress Heights station is scheduled to open in 1997.