Opponents of a MARTA expansion to Alpharetta along the east side of Ga. 400 say they don’t want a future rail or rapid-bus line rumbling through their serene neighborhoods.

About 75 residents from seven neighborhoods in Sandy Springs and Dunwoody attended a meeting at Dunwoody Community Church Thursday evening to voice concerns about the disruption a MARTA extension might cause.

Most residents said they welcome more mass transit service, but they prefer that the extension run along the west side of Ga. 400 where, they say, there are more homes, apartments and businesses that could be served by the transit system. The city of Sandy Springs also drafted a resolution in December supporting a MARTA expansion but stating a preference for building a Northridge Road station west of the highway.

“We just want to help shape MARTA in our area, and overwhelmingly no one wants the MARTA rail to come up the east side of Northridge,” said David Centofanti, president of the Northridge Community Association.

Jane McDonald, whose house is on Northridge Road, wants more public transportation in metro Atlanta. But she questioned the need for another station at Northridge Road, pointing out there are already several stations just south of the Chattahoochee River.

“I can’t believe the need is there,” McDonald said. “Are all those parking lots full?”

MARTA is eyeing a service expansion northward from the current North Springs station to Windward Parkway interchange, either with rail or a rapid-bus line. Preliminary plans call for the construction of five or six stations along that route, including one off Northridge Road.

But the mass transit system is only in the very early stages of completing a long federal study and approval process. For that reason, much about what the expansion would look like remains unclear — including whether the line would hug the east or west side of Ga. 400, according to MARTA Senior Project Manager Janide Sidifall.

In addition to the residences along the east side of Ga. 400, the building of a rail or a dedicated travel lane for buses along the east side could potentially affect to two elementary schools with about 1,500 students: Dunwoody Springs Charter and Woodland Forest.

Along that side of the highway, no organized opposition to having a rail or bus-rapid transit line appears to have crystallized. The city of Roswell supports a northward expansion of MARTA but has no position on which side of the highway it should go on, said Mayor Jere Wood.

“I’m not aware of any neighborhood movements in Roswell or Alpharetta,” Wood said. “But I’m sure there’s some folks that if it’s in their backyard would be opposed to it.”

Any expansion up Ga. 400 is at least a decade away, probably longer. There’s currently no funding set aside for what would be a $1.6 billion project (if heavy rail), $1.8 billion (if light rail) or $473 million (if rapid bus). Even if federal funding became available to help, MARTA is farther along in the study process for building a heavy rail line along I-20 East and a light rail line from Lindbergh station to Avondale.

Sidifall, the MARTA project manager, said the priority would go toward whichever project had funding lined up first.

But that doesn’t take into account the possibility of an extension into Clayton County, which could leapfrog ahead of all those projects if county residents vote in November to approve a penny sales tax to join MARTA.

MARTA has been studying the Ga. 400 corridor as a possible site for expansion for decades. Part of the frustration for residents east of Ga. 400 is that MARTA promised years ago not to expand along the east side of the highway, said Chip Swearngan, president of the Somerset neighborhood homeowners association off Northridge Road.

In 1989, the MARTA board passed a resolution stating a preference for the west side. However, since then land use, population and travel patterns have changed. Sidifall said that’s why MARTA initiated a new federal study process of the Ga. 400 corridor in 2011 that is still ongoing.

“We can’t say because we made a commitment 20 years ago we are not going to look at any other alternatives,” Sidifall said. “The feds would laugh us out the door.”