Many of the more than 10,000 residents of Red Hook credit its isolation — it is surrounded on three sides by water and cut off from the nearest subway by the Gowanus Expressway — with keeping housing costs lower, the streets quieter and gentrification slower than in other parts of Brooklyn.

However, that does not mean that the postindustrial district of crumbling brick warehouses, public housing blocks and quaint row homes has been untouched by development. Upscale boutiques now line Van Brunt Street, shells of luxury condominiums under construction dot the sleepy neighborhood, and major businesses like Tesla Motors and Ikea have moved in.

Another resident worried that the streetcar, proposed by Mayor Bill de Blasio, a Democrat, in his State of the City address last month, might further drive up housing prices and threaten the shabby charm of the district, which saw its first traffic light installed in 2006. “Red Hook is one of the few neighborhoods that’s still affordable,” said Martha Wollner, 65, who moved there in 2009. “We’re going to have a very different profile down here.”

Tom Angotti, a professor of urban planning at Hunter College, said Ms. Wollner’s fears were justified. A streetcar line “would accelerate gentrification and accelerate the displacement of industry, low-income renters and property owners,” he said. “In fact, that’s the stated objective of the proposal,” Professor Angotti said of New York City leaders’ claim that rising property tax revenues along the route could defray the estimated $2.5 billion cost of the project.

While calling the streetcar proposal “visionary,” Assemblyman Félix W. Ortiz, a Democrat whose district includes Red Hook, urged residents to get involved in the planning process to minimize the risk of displacement. “That way the community doesn’t feel that they’ve been left out,” he said.