Clang, clang.

An enthusiastic Downtown Development Authority could almost hear trolleys coming down the road Thursday after a pitch by a recent college graduate to bring the vehicles back downtown.

"I was hoping, if nothing else, it would get some wheels turning, some thoughts out there," said Ben Skinner, who spent three months planning a 4-mile trolley system snaking through Broad Street, the canal area and the medical district.

He graduated from Clemson University in December with a degree in landscape architecture. The trolley plan was his fall project.

Trolley systems aren't cheap. Mr. Skinner's proposal would cost about $175 million, or as little as $35 million with federal assistance.

The development authority voted Thursday to have one of its committees look at the idea.

Board member Paul King held up the latest issue of the Urban Land Institute's magazine, which proclaims streetcars are back in vogue.

"Bang for the buckwise, as far as capital investment in downtowns, nothing seems to have the return this has," Mr. King said. "I know it goes against some conventional wisdom out there."

Officials pointed to cities such as Portland, Ore.; Little Rock, Ark.; and Tampa, Fla., which have used light-rail systems to drum up urban revitalization efforts.

Tampa's trolley, whose route is based around historic sites, has been "huge" for that city, Mr. King said.