Former Transportation secretary Brock Adams, 77, a U.S. senator from Washington state who declined to seek reelection in 1992 amid allegations of sexual misconduct, died Sept. 10 of Parkinson's disease at his home in Stevensville, Md.

Mr. Adams, a liberal Democrat, represented Washington in the House of Representatives from 1965 to 1977 and was known for his work on transportation issues, the congressional budget process and self-government for the District of Columbia.

As Transportation secretary during the Carter administration, he advocated initiatives to reduce energy use, including increasing automobile fuel efficiency and support for mass transit.

In 1986, he was elected to the U.S. Senate. He served on the Appropriations Committee and was a consistent opponent of the Reagan and Bush administrations on numerous issues, including foreign policy and the environment. After the 1989 Exxon Valdez oil spill in Alaska's Prince William Sound, he introduced legislation that now requires oil tankers to have double hulls.

In March 1992, he ended his bid for reelection shortly after eight women who were employees or political associates told the Seattle Times that Adams had sexually harassed them.

He denied the allegations at an emotional news conference, declaring that "I've never hurt anyone," but he dropped out of the race. "He decided enough was enough," said Ellen Globokar, his chief of staff in the Senate.

Brockman Adams was born in Atlanta, but his family moved to Oregon in the late 1920s after hard times ruined his father's clothing business. He spent most of his childhood on farms in Iowa and Oregon, where the family lived with his grandfather. When he was 13, the family moved to Seattle when his father took a job with an insurance agency there.

Immediately after graduation from high school, Mr. Adams enlisted in the Navy and was assigned to the V-12 program, which allowed him to attend the University of Washington. He graduated in 1949 with a degree in economics and was accepted to Harvard Law School, receiving his law degree in 1952.

Mr. Adams returned to Seattle to practice law. In summer 1953, a senior partner at the firm where he was working introduced him to John F. Kennedy, then a freshman senator from Massachusetts. In 1960, Mr. Adams managed Kennedy's presidential campaign in western Washington. In 1961, President Kennedy appointed his friend United States attorney for the Western District of Washington.

In 1964, Mr. Adams challenged the incumbent for Washington's 7th Congressional District seat. He won a relatively easy victory with 56 percent of the votes and was reelected to six consecutive terms, sometimes with as much as 85 percent of the vote.

In the House, Mr. Adams compiled a consistently liberal voting record. He initially supported President Lyndon B. Johnson's policy in Vietnam but by 1967 had become an outspoken critic. He continued to support the president's Great Society programs.

In 1967, he became a member of the House District of Columbia Committee. He hoped to make the nation's capital a model for other cities in the way it dealt with such urban problems as pollution, transportation, crime and education.

He advocated home rule for the District to "make sure that we have democracy throughout the whole United States." He resigned from the committee in frustration in 1971 after failing to oust the committee chairman, John L. McMillan, a South Carolina Democrat who repeatedly stymied his efforts.

Mr. Adams rejoined the committee after McMillan lost a 1972 reelection bid. In 1973, as chairman of the committee's government operations subcommittee, he drafted legislation granting home rule to the District, although Congress retained the right to veto all measures approved by the mayor and council, including budgets.

Mr. Adams is generally credited with establishing the budget process in the House. Along with Sen. Edmund S. Muskie (D-Maine), he crafted the Congressional Budget and Impoundment Control Act of 1974, which called for the creation of a Budget Committee in both the Senate and the House and required that Congress create an overall budget before passing spending or revenue legislation. He became chairman of the House Budget Committee that same year.

Mr. Adams also became an expert on transportation issues.

He helped develop the Rail Passenger Service Act of 1970, which established the National Railroad Passenger Corporation, popularly known as Amtrak, and was primarily responsible for the Regional Reorganization Act of 1973, which put several insolvent railroads under the direction of the Northeast Rail Corp. Two years later, he put together a plan to consolidate seven bankrupt railroads in the Northeast and Midwest into the Consolidated Rail Corp., or Conrail.

Mr. Adams was confirmed as transportation secretary Jan. 19, 1977. He maintained that the nation had to convert its "every-industry-for-itself transportation system" into an "interlocking network." He endorsed continuing subsidies for Amtrak, approved mandatory installation of air bags in private automobiles and endorsed the construction of controversial six-lane expressways in New York City and the District of Columbia. In response to disastrous oil spills in 1976 and 1977, he mandated that tankers cruising in U.S. coastal waters must carry fully operational navigational and safety equipment.

Joan Claybrook, president of Public Citizen and former head of the National Highway Traffic Safety Administration, described Mr. Adams as "absolutely one of the best transportation secretaries we've ever had. He broke the glass ceiling for women at Transportation. He also did that at the Coast Guard. He opened up the Coast Guard for female cadets."

Mr. Adams had his differences with the White House, particularly on airline deregulation. President Jimmy Carter was an enthusiastic proponent, but Mr. Adams advocated more caution.

He crafted the 1979 federal bailout of Chrysler Corp. Alan Butchman, a lawyer who worked with Mr. Adams at the Transportation Department, recalled that his boss was the target of criticism over the size of the bailout, but "Lee Iacocca came back early with a big, fat check, and the government made out very well."

Mr. Adams resigned his Cabinet position in July 1979 as part of a Cabinet shake-up; the Wall Street Journal named him the "biggest disappointment" of Carter's Cabinet. He resumed his private law practice in the D.C. office of a Seattle law firm, Garvey Schubert Adams & Barer, focusing on transportation and Pacific Rim trade issues.

He was elected to the Senate in 1986, upsetting Republican incumbent Slade Gorton. As a senator, he consistently sought a greater congressional role over the nation's deepening involvement in the Persian Gulf. He urged President George H.W. Bush to seek "explicit authorization" from Congress before launching an attack on Iraq in retaliation for Saddam Hussein's invasion of Kuwait. He also opposed aid to the Nicaraguan Contras and Salvadoran military.

He had campaigned on a pledge to shut down Hanford Nuclear Reservation in Washington, and he opposed Department of Energy plans for making the reservation a nuclear waste depository. He also worked to preserve old-growth forests, a volatile issue in Mr. Adams's state that became a national issue symbolized by the northern spotted owl.

He was active on health issues. He sponsored legislation requiring mammography facilities to meet national quality standards; he led the effort to increase appropriations for breast cancer research; and he was an abortion rights advocate. He used his Appropriations Committee seat to push for increased funding for AIDS and cancer research.

The sexual harassment accusations in the midst of Mr. Adams's campaign for reelection "were devastating for him, his family and for the people who worked for him," Globokar said yesterday. "And yet his staff remained incredibly loyal."

Mr. Adams retired from public life at the end of his Senate term nearly a year later.

Survivors include his wife of 52 years, Mary Elizabeth Adams of Stevensville; two sons, Scott Adams of Jacksonville, Fla., and Dean Adams of Roswell, Ga.; two daughters, Kokie Adams and Aleen Adams, both of Seattle; a sister, Phyllis Hayes of Seattle; and seven grandchildren.

Brock Adams, left, shown at National Airport in a 1977 photo with Joseph Alexander of the Fairfax County Board of Supervisors, was integral in creating Amtrak and Conrail.