William T. Druhan Jr., 63, an electrical engineer who led efforts to slow the growth of the Loudoun County community of Purcellville, and who served as mayor when it was the fastest-growing town in the fastest-growing county in the United States, died June 24 at his home. He had pancreatic cancer.

Mr. Druhan settled in Purcellville in 1980, when it was a rural hamlet of 1,567 residents.

During the 1990s, the town, about 50 miles west of Washington, doubled in size. That prompted Mr. Druhan to start a group called Concerned Citizens of Purcellville, whose members feared the town was losing its quiet character to rapid annexation and housing construction.

To try to slow down traffic, Mr. Druhan armed himself with a radar gun and video camera. After sometimes tense confrontations with neighbors, his permit to operate the radar was revoked by the police chief.

Leading a coalition of slow-growth candidates, Mr. Druhan ran for Purcellville mayor in May 2000 under the slogan of “Take back our town!” The election drew more than 900 voters to the polls — up from 107 in the previous mayoral race — and it had residents locked in fierce debate.

William T. Druhan Jr. was mayor of Purcellville from 2002 to 2006. (Tracy A. Woodward/WASHINGTON POST)

“The campaign had more color and controversy than the town has ever seen — some said it bested the big fires of 1914 to become ‘the biggest’ event ever,” The Washington Post reported.

When the ballots were counted, Mr. Druhan lost to incumbent John D. Marsh by 23 votes, 470 to 447.

In 2002, with an even larger turnout, Mr. Druhan handily won the mayor’s race and was reelected two years later. He sought with mixed success to limit Purcellville’s expansion at a time when Loudoun was growing more quickly than any other jurisdiction in the country.

He coordinated a plan for downtown restoration and redevelopment, created a board of architectural review, and oversaw beautification efforts and improvements to infrastructure.

In 2004, when the owners of a property on East Main Street cut down six mature maple trees to build a parking lot, an incensed Mr. Druhan helped establish a commission to prevent rampant tree removal.

He stepped down as mayor in 2006 but continued to serve on the town’s planning commission and a parks and recreation advisory board. Purcellville’s population is now about 7,000.

William Thomas Druhan Jr. was born July 4, 1947, in Madison, Wis. He grew up in Silver Spring and England, where his father was an accountant for the General Accounting Office.

After graduating from Albert Einstein High School in Kensington in 1965, Mr. Druhan served in the Navy for four years and was a veteran of the Vietnam War.

He graduated from the University of Maryland and worked as an electrical engineer for the Annapolis office of the IIT Research Institute for several years, analyzing radio and radar equipment. He later worked for the Commerce and Defense departments and, until his death, Sentel.

His marriages to Tessa McAllister and Laurie Druhan ended in divorce.

Survivors include his wife of 20 years, Tammy Bugg Druhan, and their two children, Joseph Druhan and Margaret Druhan, both of Purcellville; a sister, Mary Ruttkay of Garrett Park; and four brothers, Michael Druhan of Madison, Wis., Stephen Druhan of Takoma Park, John Druhan of Reisterstown, Md., and Philip Druhan of Bethesda.

Mr. Druhan was a member of the Lions Club, American Legion, Eagles and the Purcellville Volunteer Rescue Squad. Although he was not particularly religious, he played Pontius Pilate in the town’s production of the Passion Play for more than 20 years.

He went to Montreal each year to attend a Formula One race.

Mr. Druhan said that the five years he spent as a child in England influenced his later thinking on town planning.

“They did their planning well, with lots of footpaths, a rail station, a good bus system,” he told The Post in 2002. “They managed their land planning and water without crowding the place, and that’s exactly what we need to be doing here.”