Douglas F. Schneiderman, 51, a partner in his family’s Washington area real estate development company, Madison Homes, died July 29 after a two-car collision in East Hampton, N.Y., on Long Island. He was a McLean resident and was on vacation in Amagansett, N.Y., near East Hampton.

According to East Hampton police, Mr. Schneiderman was driving north on a state road when his vehicle collided with an oncoming pickup truck that crossed into his lane. Mr. Schneiderman was pronounced dead at the scene. His wife, Lisa Bangert, and a daughter, Rachael, were hospitalized with injuries that authorities said were not life-threatening. The other driver was also hospitalized. The accident was under investigation.

Madison Homes was formed in 1992 by Milton Schneiderman, who is Douglas’s father, and Russell Rosenberger. It remains one of the few family-owned real estate companies in the Washington area still building “in any significant way,” said Bill Regardie, publisher of the now-defunct Regardie’s magazine, which focused on business in the Washington region.

The Schneidermans developed thousands of homes and condominiums, including Portner’s Landing in Alexandria, McLean Village and Acton’s Landing in Annapolis.

Douglas Foster Schneiderman was a native of Queens and a 1983 community development graduate of the University of New Hampshire. He received a master’s degree in business administration from George Washington University in 1986.

He joined the now-defunct Milton Co., started by his father, in the 1980s. He became a partner in Madison Homes in 1998.

His first marriage, to Carol Bauer, ended in divorce.

Survivors include his wife of 18 years, Elisabeth “Lisa” Bangert, and their two daughters, Isabelle Schneiderman and Rachael Schneiderman, all of McLean; a stepdaughter, Torie Kouri of Burke; his father and stepmother, Milton and Karen Schneiderman of Washington; his mother, Sandra Schneiderman of Manhattan; a sister; two half sisters; and a grandson.

— Adam Bernstein