It is 6.3 miles over winding roads through the spacious, beautifully landscaped subdivisions from Audrey Moore's house just off the Little River Turnpike past the Beltway in Annandale to Jack Herrity's house off Rolling Road in West Springfield. Today cars wait two or three cycles to get through each traffic light; 40 years ago this was mostly open country and most of the subdivisions didn't exist. Fairfax County just after World War II had as much farmland as a county in Iowa; today it has a population larger than that of the central cities of Boston or Cleveland or Washington. Most of the people voting in this week's county board chairman race didn't grow up in Fairfax. Neither did the two candidates.

Moore grew up in Larchmont, New York, an old suburb on Long Island Sound that was and is affluent and Republican: "I think I'm the only Democrat in the family." Her father was in the oil business, and she was born in Venezuela, where he was working for Standard Oil in the 1920s; she has memories of "a little puppy dog that went into a creek full of piranhas" and didn't come out. When she was still little they sailed back to New York, where her father started a business at the height of the Depression, selling oil-field equipment abroad: he was a middleman between manufacturers who didn't want to bother with export red tape and big oil companies that didn't want to shop around among manufacturers. It was a business that required lots of hustle and initiative, and lots of entertaining and travel, until he became successful enough to hire others. He made a good living in New York and then came back on the train to leafy Larchmont.

Larchmont, as Moore remembers it, was "just beginning to go downhill." She remembers returning from Jones Beach hot and sticky in hours of traffic and how "you didn't go anywhere on weekends the traffic was so horrendous." The oldest of three daughters, she went to a girls' school in Massachusetts, to Mount Holyoke briefly, then to the University of New Hampshire. ("I was sick of girls' schools," she said.) Engaged to a Maryland law student, she moved after graduating to College Park; she broke up with him and met and married Sam Moore, a Navy and then Interior Department employee. Answering a Sunday want ad, she got a job with Anna Van Sickler, who lobbied and represented oil and coal companies on trademark and export business; in the Korean war she walked applications for export licenses from one desk in the temporary buildings on Constitution Avenue to another. "No builder needs to tell me about red tape."

Moore got into politics after years as a housewife raising three sons. She says she wanted to prevent in Fairfax what she saw in Larchmont. She was angry that the scandal-tarred supervisors elected in 1963 opened up the whole county to development, that builders weren't required to pay for streets or proper drainage, that the people attracted by the county's good schools wouldn't get enough parkland. And now there are patches of parkland all over the county, some huge, many small, one with an athletic oval not far from the red brick, white-shuttered, 1950s vintage house -- a small house with a big yard -- where Moore has lived since 1960.

Herrity came from a family of elevator people: men who installed and serviced elevators. His grandfather came over from Ireland, worked on elevators, "was a union person"; he had six children, most of whom became elevator people or married their children; his father had his own small elevator service company, and his uncle worked for Otis servicing the county's Massey Building elevators: it was one of those crafts in which sons follow fathers. Herrity's father was an elevator man, and the family lived in Arlington, which in those days was filled with more empty lots than houses, and then moved to Prince Georges County. Herrity went to St. Charles Elementary in Clarendon and commuted to St. Anthony's High School in Northeast Washington, where he was an aggressive, but hard-to-control athlete and had "a miserable record." Unable to get into college, he joined the Coast Guard and served aboard ship in the Far East from 1951 to 1954.

The G.I. Bill of Rights, that great stairway of upward mobility, gave Herrity a second chance to go to college, and the Georgetown School of Foreign Service accepted him conditionally; he worked hard, graduated in 1957, and went on to graduate and law school. He worked as a title attorney and got a job at the National Labor Relations Board, and in the 1960s he went to work as a labor relations lawyer for a company in Cincinnati. He didn't like it: "if you're not born there you're nothing." So he came back to the Washington area and went into the insurance business in Springfield, fashioning employee benefits and pension plans for the growing number of businessmen out in the suburbs. In 1965 Herrity, his wife and five children moved into a tan brick two-story house on a cul-de-sac, bordering a park, in a closely-packed but nicely wooded subdivision that was the first built in the Pohick watershed; like most of his homes, it was at the far edge of the metropolitan area's expansion.

In the years when Audrey Moore, who grew up in an affluent Republican household, was working in the League of Women Voters and the Democratic party to limit growth, Jack Herrity, who grew up in a Democratic family, was president of his civic association and a Democratic precinct captain and county committeeman. In 1971 Moore as a Democrat and Herrity as a Republican ran for supervisor from adjoining districts. They were both elected and have served (Herrity as chairman since 1975) together ever since, as geographical neighbors and political adversaries, the polite but persistent critic and the aggressive and blunt booster of Fairfax's growth, people who came to the suburbs of Fairfax County on different paths and want to see it take different paths in the future. The writer is a member of the editorial page staff.