Mr. Woodbridge, seen here in 1974, was instrumental in the blueprint for renovating Pennsylvania Avenue in Washington, D.C. According to William Anderson Barnes, an executive director of the project, Woodbridge helped change the avenue “from a place that was pretty much a 9-to-5 institutional government building kind of place into something that was a 24/7 kind of place with theaters, restaurants, retail, art galleries — the whole thing.” (Geoff Causton/The Washington Post)

John M. Woodbridge, an architect who helped launch the transformation of Pennsylvania Avenue in the 1970s from an scruffy thoroughfare into a showcase for urban living and inaugural parades, died June 2 while traveling in Saint-Paul-de-Baïse, a town in southern France. He was 85.

The cause was a heart attack, said his son, Larry Woodbridge.

Mr. Woodbridge was one of many architects and city planners over the years, beginning in the late 1700s with Pierre Charles L’Enfant, who helped shape the boulevard that connects the U.S. Capitol and the White House — “symbolizing,” the late U.S. Sen. Daniel Patrick Moynihan once wrote, “at once the separation of powers and the fundamental unity in the American Government.”

Mr. Woodbridge came to the project in the early 1960s, when Pennsylvania Avenue was marked by a shabby succession of rundown buildings and vacant lots. President John F. Kennedy was said to have lamented the lack of grandeur in the boulevard, which serves as the key portion of the inaugural parade route.

Nathaniel A. Owings, the noted architect, became head of a presidential commission that would undertake a massive renovation. Mr. Woodbridge, then associated with the Skidmore, Owings & Merrill architecture firm, became chief of design. In 1972, when Congress established the Pennsylvania Avenue Development Corp., he became its executive director.

A view of the northwest quadrant of Pennsylvania Avenue in November 1963. (Robert McNamara/The Washington Post)

From the start, the project was complicated by conflicting visions for the cityscape. Initially, and in keeping with the philosophy of the era, designers had proposed a dramatic overhaul entailing the removal of several blocks — along with buildings including the historic Willard hotel — to create a grand plaza.

“One day, we sketched it quickly and put it up on the wall,” Mr. Woodbridge told The Washington Post years later. “I woke up the next morning, worrying, ‘What have we done?’

“That was the way we worked in the ’60s, planning was all done by the ‘Big Idea,’ without much thought about who would have to be relocated or what the impact would be on people’s lives,” he continued. “I thank God now, that it never came to pass. But I remember thinking then, ‘Don’t worry, it won’t ever get built.’ ”

The plan was ultimately discarded. In response to new trends in urban design, and working with a team of architects and planners, Mr. Woodbridge led the development of another design that outlined a mix of commercial, retail, cultural, public and residential space that also would be welcoming to pedestrians.

Mr. Woodbridge did not want Pennsylvania Avenue to be “a place that died in the evening,” said Jo-Ann Neuhaus, a longtime employee of the development corporation who today leads the Pennsylvania Quarter Neighborhood Association.

Yong-Duk Chyun, an architect who worked with Mr. Woodbridge at the corporation, credited him with attending to not only the grand aspects of the avenue but also details such as street lights, tree grates and benches — the “delicate elements,” Chyun said, that are “part of the vocabulary of the entire avenue’s design.”

Mr. Woodbridge left the Pennsylvania Avenue Development Corp. in 1977, remarking that he was an architect and that the organization needed a developer to complete the project. William Anderson “Andy” Barnes, a subsequent executive director, credited him with having “really laid out the blueprint for what needed to be done.”

An evening view of the Old Post Office Pavilion, at left, and Pennsylvania Ave. NW in 2012. (Tracy A. Woodward/The Washington Post)

Mr. Woodbridge helped change the avenue, Barnes said, “from a place that was pretty much a 9-to-5 institutional government building kind of place into something that was a 24/7 kind of place with theaters, restaurants, retail, art galleries — the whole thing.”

When the development corporation closed in 1996, The Post reported that it had received $150 million in federal appropriations and that it had generated $1.5 billion in private development. Its efforts added parks and hundreds of trees.

“Pennsylvania Avenue has been transformed from an undistinguished urban district in 1972 into a very desirable place to work, live, dine, shop, and visit,” declared the Urban Land Institute, according to the Chicago Tribune, in a 1994 recognition of the project. “Through foresight and patience, the area’s negative image was overcome and private capital was attracted for renovation and new construction.”

John Marshall Woodbridge was born Jan. 26, 1929, in New York. His father was an architect, and his mother was the headmistress of a private school in Manhattan. He was a 1951 graduate of Amherst College in Massachusetts and received a master of fine arts degree in architecture from Princeton University in 1956.

While at Skidmore, Owings & Merrill, Mr. Woodbridge also played a leading part in the design of projects including the reflecting pool at the base of the Capitol, said his son.

Mr. Woodbridge moved in the late 1970s from Washington to California, where he continued his architectural career and co-authored several books on California architecture. At the time of his death, he was a Sonoma, Calif., resident.

His first marriage, to Sally Byrne Woodbridge, ended in divorce. Survivors include his wife of 39 years, the Pulitzer Prize-winning poet Carolyn Kizer of Sonoma; two children from his first marriage, Larry Woodbridge of Brooklyn and Pamela Woodbridge of Berkeley, Calif.; three stepchildren, Ashley Bullitt of Seattle, Fred Nemo of Portland, Ore., and Jill Bullitt of Hudson, N.Y.; a sister, Jane Woodbridge Sieverts of Washington; nine grandchildren; and one great-grandchild.

When Mr. Woodbridge left the development corporation, years before the new Pennsylvania Avenue was complete, he had already envisioned the final result.

“I look forward to the day when I can walk down the avenue, on a wide sidewalk, sheltered by a canopy of trees,” he told The Post. “Those rows of trees — Jefferson proposed them long ago — will bring it all together, and give us at last, our grand avenue.”