It’s not hard to find support for expanding MARTA service in North Fulton County. What is challenging is getting the cash to build it.

That’s not stopping MARTA from laying the groundwork in case future funding becomes available, though.

MARTA filed a notice to the Federal Transit Administration last week that it will hold a public meeting to get input about the potential for adding buses, light rail or heavy rail along a 12-mile stretch of Ga. 400 from Dunwoody to Alpharetta.

Currently the last stop on the MARTA red line is the North Springs station directly off Ga. 400 in Dunwoody.

The plan to expand northward is pie-in-the-sky for now because MARTA doesn’t have the money and has not identified another source of local, federal or private-sector investment. Janide Sidifall, project manager for the Ga. 400 transit iniative, said the agency’s latest move is neither a big step nor a baby step, but it’s “planning to one day take a step” in what is at least a 10-year federal planning process.

As it’s being shaped, the Ga. 400 transit expansion plan could involve adding rapid-transit bus service, with a dedicated lane where buses could bypass congestion. The current MARTA and Express bus service fights the same traffic congestion automobile drivers do.

Or, it could involve light rail (such as streetcars) from the existing North Springs MARTA station to Windward Parkway. That would include constructing as many as six stations, at Northridge, Holcomb Bridge, Mansell Road, North Point Mall, Old Milton and Windward Parkway.

A third option is to extend the existing heavy rail line, which would involve constructing all of those stations except the one at Old Milton.

Heavy rail would be the most expensive option, but it would probably attract the most passengers, Sidifall said.

Details about the cost and potential ridership of the proposed expansion were not available Thursday. However, officials said those figures would be presented at the public hearing, 6:30-8:30 p.m. Sept. 26 at Alpharetta City Hall. Written comments can also be emailed to connect400@itsmarta.com.

Yvonne Williams, president of Perimeter Community Improvement District said the four MARTA stations (Dunwoody, Medical Center, North Springs and Sandy Springs) in her 4.2-mile self-taxing business district are a big reason so many corporations have moved to the Perimeter Mall area. She fully supports an expanded transit service.

“It shows you that we have a backbone we need to build off of,” Williams said. “MARTA has been very popular for years … it’s important to build off it and make it as functional as possible.”

Some are still wary of a MARTA expansion, citing the agency’s history of mismanagement and its declining ridership. Tom Cork, a Roswell resident who was a member of the now-defunct Tea Party of North Fulton, said he would favor bus service, but only if it was privatized. He opposes MARTA rail expansion.

“It’s foolish to even think about putting down a permanent rail system,” Cork said. “The ridership is low, you have to subsidize it and behind that comes repair and maintenance costs. That goes on and on indefinitely through several lifetimes.”

MARTA has been studying an extension of the North Springs line since at least 2003. At that time, the area was deemed to be “not transit supportive” due to a combination of high incomes and low household and employment density.

MARTA initiated another analysis of the Ga. 400 corridor in late 2011, and that analysis is still ongoing.

MARTA is slightly farther along in the study process when it comes to two other proposed expansion lines. One is a $1.16 billion light-rail line from the Lindbergh station to Avondale, which is 8.8 miles and would serve 10 stops. Another is a 12-mile extension of the heavy rail line along I-20 East from Indian Creek to the Mall at Stone Crest, which would involve adding five stations.

All these plans could come in handy if the federal funding tap someday reopens, however unlikely that may seem in today’s fiscal climate.

It happened before, in 2010, when the Obama administration put forth a stimulus program that included $8 billion to jump-start a high-speed intercity passenger rail service around the country.

Cities like Tampa and Charlotte benefited. However, Georgia lost out, partly because it did not have any eligible projects in the pipeline.