One idea to beat Seaport traffic: Glide over it

An aerial tram in Portland, Ore. Could a similar contraption be headed for the Seaport?Leah Nash/The New York Times, File

Here’s a wild idea for dealing with traffic congestion along the South Boston Waterfront: Just glide right over it.

A major Boston development firm is proposing to build an aerial gondola or cable car system to transport as many as 15,000 people a day between South Station and the Seaport District.

The proposal is very preliminary, and, yes, sounds a bit fanciful. But the firm, Millennium Partners, said it is willing to cough up as much as $100 million for the elevated project, and US Representative Stephen Lynch is signaling that he is receptive to the idea.

Millennium Partners, which built Millennium Tower in Downtown Crossing, said Friday it has begun briefing city and state officials about bringing the off-beat mode of transportation to the booming but congested neighborhood.

A Millennium subsidiary, Cargo Ventures, controls land in the Raymond L. Flynn Marine Park. The company believes a gondola system, running in a line along Summer Street between Marine Park and South Station, could move 15,000 commuters a day.

Michael Vaughan, a spokesman for Millennium, said the idea is in the early stages, but he championed it as an “innovative solution” for the Seaport’s traffic problems.

“We can’t continue to focus on the same old things like shuttles and water taxis,” Vaughan said. “This is an application that’s totally different, totally doable and would serve not just our project, but the industrial park and the South Boston community.”

Cargo Ventures controls about 12 acres between Northern and Drydock avenues, where the Boston Planning and Development Agency envisions sizable new development. Vaughan said the site has the potential to host thousands of new jobs and he expects Cargo Ventures to release specifics on its building proposal once a new city master plan is approved by the state.

The company’s agreement with the city stipulates Cargo Ventures spend up to $100 million toward transportation to offset the increase in traffic in the area.

The gondola would the latest — and certainly the most unusual — example of private developers helping to underwrite public transit in the Boston area.

Cable-car systems have popped up elsewhere in the world, including aerial trams in New York City, Portland, Ore., and Medellin, Colombia. They are often built to scale steep hills or cross bodies of water.

The Portland system, opened in 2007 at a cost of $57 million, runs 3,300 feet between the city’s waterfront and the Oregon Health & Science University, and the 78-passenger trams cover the trip in four minutes.

In Boston, key aspects of the idea remain undetermined, including the gondola’s height and its exact route.

But the idea has piqued the interest of Lynch, whose district includes the South Boston Waterfront.

“It’s one of the few proposals I’ve seen that doesn’t put more cars on the road,” he said in an interview with Boston Herald Radio on Friday.

Lynch said that by his understanding, the proposed gondola system would involve cable cars that could fit as many as 40 passengers. He’d prefer the system be owned and operated by the Massachusetts Bay Transportation Authority, arguing a private operator might charge too much.

The MBTA declined to comment and referred questions to the Massachusetts Department of Transportation.

MassDOT spokeswoman Jacquelyn Goddard said the agency is “always willing to have conversations with local, public, and private entities about opportunities to improve transit.”

However, she said, the agency is currently focusing on other ways to improve Seaport transportation, such as providing better Silver Line service, launching a ferry service, and improving bike and pedestrian infrastructure.

Other government agencies stressed that the idea is preliminary. The Boston Planning and Development Agency, which owns the Marine Park, said a “formal proposal is not before us at this time.”

And Jennifer Mehigan, a spokeswoman for the Massachusetts Port Authority, which owns land in the Seaport, said the agency has heard a little about the aerial tramway. “There have been a lot of good ideas focused on reducing traffic in the South Boston Waterfront. We received some preliminary information on this one,” she said.

Lynch could not be reached for further comment Friday.