Carmen E. Turner, 61, the former general manager of the Washington Metropolitan Area Transit Authority who presided over a critical period of construction, growth and operation of the area's rail and bus system, died of cancer yesterday at Washington Hospital Center.

Turner was Metro's general manager from 1983 to 1990. In that period she directed expansion of the rail system from 42 miles and 47 stations to 70 miles and 63 stations, changing forever the commuting patterns and leisure-time habits of thousands of residents of the Washington area.

Another 20 miles of Metrorail were under construction and scheduled to open in stages during the next three years when she resigned to become undersecretary of the Smithsonian Institution. Shortly before leaving Metro, Turner won a commitment from Congress to fund completion of the full 103-mile Metrorail system.

She was the first of Metro's general managers to guide the agency's transformation from an organization primarily concerned with building a mass transit system into one with equally vital operating responsibilities. When she left for the number two job at the Smithsonian, Metro's work force was 9,000 and daily ridership was 1 million. Its operating budget was $612 million.

As Metro's chief operating officer, Turner led a delicate and sometimes uneasy coalition of officials representing eight city and county governments, many of whom had strongly conflicting views on how the system should serve its varied constituency, city and suburban, rich and poor, black and white.

She was known as a deft administrator with a sharp and nimble mind and a low tolerance for incompetence. Her style of operating was said to be warm, charming and non-confrontational, but she also demanded answers and solutions whenever anything went wrong. She was politically astute and an unabashed supporter of Metro, and she was extraordinarily effective at getting her way when it came to what she perceived as the best interests of the Metro system.

Her decision to leave Metro for the Smithsonian was "heart-wrenching," she said. "Metro's been my baby . . . . Metro's a healthy organization. It has a good, solid work force . . . . You know people say there are three things that bind us together. One of them is the Redskins, of course. One is the Smithsonian. And of course you know what the third is -- Metro."

At the Smithsonian, Turner became chief operating officer of an organization under severe managerial stress and, like Metro, facing extreme financial difficulties. She was hired by the Smithsonian's secretary, Robert McC. Adams, whose management style had been perceived as erratic, aloof and contributing to staff morale problems. A search committee recommended Turner for the job largely because of her proven skills at lobbying on Metro's behalf and her track record as an administrator.

Her first assignment at the Smithsonian was to direct a reorganization of the institution, which had been under fire on Capitol Hill for failing to set its priorities. She had been on the job less than a year when her breast cancer was diagnosed. By the fall of 1991, she was working out of her home in Washington.

A native of Teaneck, N.J., Carmen E. Pawley spent her early childhood in northern New Jersey, where her father was executive director of the Urban League of Essex County. She and her sister were the only black children in their elementary school in Englewood. They moved to Washington in the late 1930s, where they found themselves in rigidly segregated schools and where black people could not sit at lunch counters or eat at restaurants downtown.

She graduated from Dunbar High School, then entered Howard University. She eloped with a classmate, Frederick B. Turner Jr., during her sophomore year and dropped out of college, much to the distress of her parents.

She had two sons, went to work as a government clerk-typist and returned to Howard, where she completed her bachelor's degree. She continued her studies at American University, where she received a master's degree in public administration and completed everything but her dissertation for a doctorate in American government.

During that period she also rose through the federal bureaucracy in a variety of jobs and agencies. She joined the Department of Transportation's Urban Mass Transportation Administration in 1974 after working as an administrative assistant for the Department of the Army, and she was a civil rights officer there when Transportation Secretary William T. Coleman appointed her acting director of DOT's civil rights office in 1976.

In 1977, Metro's general manager, Theodore C. Lutz, offered her a job as Metro's chief of administration. Wanting to move away from affirmative action-related positions, she accepted. That was a year after the first Metrorail trains began running.

When Lutz's successor, Richard S. Page, left Metro in 1983, Turner was one of the few high-level Metro executives who didn't apply for his job, so the board asked her to serve as acting general manager while it looked for a replacement. The search took longer than expected, but the agency continued to operate smoothly in the interim, so the board voted unanimously to offer Turner the job permanently. She accepted and became the first black woman to head a major U.S. transit system.

Her stewardship coincided with a period of turbulence in the District government; by contrast, Metro operated smoothly. The subway became a major tourist attraction, praised by its promoters as "America's subway," and in 1988 Metro won the transit industry's highest award as the best bus and rail system in North America.

In 1989, Turner was named transit manager of the year by the American Public Transit Association, which saluted her as the manager "who has done the most to advance the urban transit industry in the United States and Canada."

Her years at Metro's helm came during a time of economic prosperity, and they fell within the period when Metrorail equipment was new and in good working order. Both of those factors contributed to Turner's success. Fares did not have to be raised, and there were few breakdowns.

Still, her administration was not without blemishes. She was humiliated when back-to-back snowstorms shut down the rail system in the winter of 1987. But her lowest point was probably Metro's failure to open the first Green Line stations in the Shaw neighborhood of Northwest Washington on time. That line, designed to serve some of the city's poorer neighborhoods, was stalled by court battles, construction delays and controversy and did not open until after Turner left Metro.

In the meantime, that area's recovery from the devastation of the 1968 riots was held in abeyance and the isolation of Shaw's businesses was prolonged as residents lived amid ripped-up streets and gaping holes in the earth.

Mitch Snyder, the late advocate for the city's homeless population, accused Turner of "a real lack of sensitivity" for failing to back down when he went on a hunger strike in 1987 to protest Metro's decision to install iron gates to keep homeless people from sleeping in Metro stations at night. "She didn't deal with the issue on a human level. She dealt with it strictly on a managerial level, a professional level," Snyder said.

Turner's response: "I have no comment because I'm a pragmatist."

When she became Metro's general manager, Turner was already a proven administrator, but she had little experience in engineering. She learned how to drive a bus, took a course in rail maintenance and studied techniques of underground construction.

She was known on the job for persistence and a sense of humor but also for a commanding presence that was once described as "regal."

She enjoyed getting out and meeting Metro employees and riders, but she had a bureaucratic way of expressing that. "What really drives me is that I really like people. I enjoy the human interface," she said.

Turner served on the boards of trustees of Howard and George Washington universities. In 1988 she was co-chairman of the D.C. Committee on Public Education, a group formed to conduct an evaluation of D.C. public schools and develop a plan for improving them.

In addition to her husband, of Washington, survivors include two sons, Frederick B. Turner III of Canoga Park, Calif., and Douglas P. Turner of Washington; her mother, Carmen Pawley of Silver Spring; a sister, Dr. Dolores Dickerson of Silver Spring; and two grandchildren.