There's an experiment taking place on Peachtree Street that could influence Atlanta's future for generations. It's just that nobody knows it's there.

??

"My biggest disappointment is that nobody knows about it," says Buckhead Coalition President Sam Massell. "Everywhere I go, people say it's a great idea, but they haven't heard about it."

??

The big secret is a MARTA bus route — nicknamed the Peach and featuring peach-colored buses — that runs up and down Peachtree all day long in 30-minute increments.

??

What sets it apart from the rest of the city's public transportation is that it's the first bus route in MARTA's 35-year history that allows riders to travel between downtown and Buckhead while staying in one seat — that is, without needing to transfer to a train or another bus.

??

The Peach, known officially as Route 110, was quietly launched by MARTA in October after lobbying by Massell and other civic leaders who argued that providing commuters and residents along Atlanta's signature street with convenient local transportation could help eliminate some short car trips.

??

But the primary reason Route 110 warrants attention is that it serves as something of a trial run of the proposed Peachtree streetcar — minus the actual streetcars.

??

The prospective 12-mile streetcar line linking West End to Buckhead has been championed by business luminaries who organized an advocacy group, Atlanta Streetcar Inc. A study commissioned by that group estimates that a streetcar line along Peachtree could generate more than $4 billion in new development along the street.

??

Last year, Mayor Shirley Franklin appointed a blue-ribbon panel of civic leaders to propose development and design guidelines for Atlanta's most famous thoroughfare. A streetcar line is expected to be chief among their recommendations.

??

Massell, a former Atlanta mayor who is not known as a streetcar supporter, says that if the bus does well, it will show streetcar supporters that there's a market.

??

But without publicity — apart from a large link on the MARTA website — the route has been slow to catch on. In Massell's view, the tourists and local commuters who would seem to be the target customers for the Peach are largely unaware of its existence.

??

On a recent weekday, nearly all of the riders on the hour-long trip between Five Points Station downtown and Lenox Square — the route's northern terminus — seemed to be the kind of regular MARTA patrons who might have ridden the old bus routes 10 and 23 that Route 110 replaced.

??

MARTA spokeswoman Cara Hodgson says the agency hasn't kept close track of numbers for the new route, but polls show about 10 percent of its riders are new. "We've seen a modest increase in ridership," she says.

??

At least that's better than MARTA's other recent initiative. At last count, the Tourist Loop, a bus route that carries riders to downtown and Midtown attractions, was running at less than one-third of its ridership goals.