WASHINGTON — Washington residents cheered the return of professional baseball to the American capital last year after a 33-year absence. Soon, they’ll be able to look back to the future again.

The city is planning a $25 million project to bring back the trolley cars that last rumbled along its streets during the Kennedy administration. The revival will begin next year with a 2-mile line in southeastern Washington that, fittingly, will pass near the Washington Nationals’ new downtown ballpark, which is to open in April 2008.

“To have baseball and streetcars come back somehow makes the city seem whole,” a city transportation agency worker, Eric Madison, said. Mr. Madison, 32, volunteers at the National Capital Trolley Museum, which saved parts of the trolley fleet after the lines were torn up in 1962 in favor of subways and buses.

City planners are looking beyond the dreams of nostalgia buffs for trolleys to help spur economic development, cut pollution, and ease traffic congestion. The Washington area ranks third in America in gridlock, behind Los Angeles and San Francisco, according to a 2005 study by the Texas Transportation Institute.

“Light rail is the wave of the future if you care about the environment,” Washington’s delegate to Congress, Eleanor Holmes Norton, said. Ms. Norton, 69, said she expects fellow Democrats, who take control of Congress in January, to boost funding for such projects across America.

The streetcar line, being financed by the city, is part of an initiative to revitalize one of Washington’s poorest neighborhoods, along the Anacostia River. Almost 30% of its residents live below the poverty line and unemployment is three times the national average, according to a local group, East of the River Community Development Corp.

“A lot of times, when streetcar systems are put into areas that are distressed or undergoing some kind of economic change, economic development occurs around the area of the fixed investment,” the city Transportation Department’s coordinator for the streetcar project, Catondra Noye, said.

Washington is mainly counting on the Nationals’ $611 million ballpark to draw $1 billion in investment for housing, stores, and offices in the waterfront neighborhood, replacing a drab 1960s-era mall and rundown nightclubs. The city has spent $150 million on riverwalks and parks along both banks of the Anacostia. Trolley and pedestrian bridges are planned, starting in 2011.

The new red-and-yellow articulated cars, built by Prague-based Inekon Group, will have a “sleek, modern look,” Ms. Noye said. They will run on electric power from overhead wires. While initial plans only call for the Anacostia line and another along H Street in the northeast, the city eventually wants streetcars along seven major transportation corridors.

Streetcars once dominated Washington’s traffic grid. But prosperity, cheap gasoline, and a surge of automobiles spelled doom for the streetcars, which were plagued by a reputation for clogging streets and being “too cold in winter, too hot in summer,” Ms. Norton recalled.

By January 1962, the streetcar ended its run, with the no-longer-needed cars sold to European cities from Barcelona to Sarajevo.

Washington’s plans are welcome news to streetcar buffs at the National Capital Trolley Museum in Silver Spring, Md., where a handful of the surviving old cars are kept in working order by volunteers.