Keith Parker had run large-scale transit operations in Charlotte and San Antonio, but he realized from the start that Atlanta would be his toughest assignment yet.

The beleaguered Metropolitan Atlanta Rapid Transit Authority (MARTA) is the ninth-largest enterprise of its kind in the country. But ever since its beginnings in the early 1970s, it has been ensnared in racial, regional and partisan acrimony. Georgia’s state legislators have never been shy to criticize or to micromanage the agency, which they have denounced as inefficient and unreliable. Originally envisioned as a five-county system, MARTA has never been able to expand beyond its initial two counties in the center of the Atlanta metropolis.

Much of MARTA’s problem has always been its unorthodox funding mechanism. Most of the nation’s public transit agencies get about a quarter of their income from state funds, but MARTA doesn’t get any operating money at all from the state of Georgia. Its budget is heavily dependent on local sales taxes, leaving the system especially vulnerable to economic downturns. During the Great Recession, MARTA took a cleaver to its operating expenses. A third of its bus routes were eliminated. Wait times between trains hit 15 minutes. Bathrooms in most stations were closed. Along with reduced services, passengers saw fares rise more than 40 percent. Customers were incensed. Ridership dropped by a sixth in the four years before Parker arrived.

“Many people in the transit industry view the MARTA job as the most complex one in the entire industry,” Parker told Atlanta reporters shortly after being named the agency’s general manager and CEO in October 2012. “I don’t disagree.”

That was two months before Parker officially started the job. Once he moved in, he would discover MARTA’s problems were even deeper than he had imagined. Still, he dug in and has pleasantly surprised some of the agency’s most persistent critics.

Parker wasn’t the first MARTA manager to promise an improvement in the agency’s fortunes, but most of the previous efforts had ended in disappointment. Parker’s predecessor, Beverly Scott, who now leads Boston’s transit agency, said one of the reasons she took the Atlanta job was that she believed MARTA and the region were on the cusp of a turnaround. The recession chilled any thoughts of recovery, and Scott spent most of her five-year tenure just trying to keep the agency afloat. Still, Scott and the MARTA board did commission an audit by the consulting firm KPMG that identified many ways the agency could shore up its bottom line. Parker and the board have used that audit as an owner’s manual in setting about to overhaul the agency.

Unlike most of his MARTA predecessors, Parker has been helped by economic and demographic changes. The city of Atlanta has been attracting more affluent residents, many of them drawn to walkable neighborhoods with good access to transit. Commercial construction is finally restarting after the slump of the recession, and many of the new projects are near MARTA lines. State Farm, for example, just broke ground for a major new campus that includes a 26-story tower linking directly to the agency’s Dunwoody station.

Atlanta Mayor Kasim Reed has championed the reintroduction of streetcars to the city. The first streetcar line, which follows a nearly three-mile route through downtown and adjoining neighborhoods, is scheduled to start running by the end of the year. Plans call for it to eventually link up with the new BeltLine, a string of parks and trails that will someday encircle the city. While the city has taken the lead in developing the high-profile streetcar system, MARTA has been playing a role as well.

But for all the favorable outside news, community leaders say the biggest factor in MARTA’s transformation is Keith Parker. “The reality is that a different general manager might not be delivering the results we are now seeing,” says state Rep. Mike Jacobs, a Republican who chairs the legislature’s MARTA oversight committee.

Parker came to Atlanta with a history of making big improvements while operating across party lines. In San Antonio, working in a Democratic city in a Republican state, he oversaw huge growth in bus ridership. In Charlotte, where he presided over the installation of a much-heralded light rail system, Parker worked with two mayors: Pat McCrory, now the Republican governor of North Carolina, and Anthony Foxx, a Democrat who is now President Obama’s transportation secretary.

He used those experiences to help resuscitate MARTA’s bad image. When he introduced himself to the Atlanta media at his initial press conference, Parker let Atlanta residents know he was looking for a house near a MARTA rail station. Parker, who is 48 years old, appears frequently on Atlanta TV, in ads and in the news. With his shaved head and closely cropped goatee, he is easily recognizable. He’s also easy to spot on the train, which he takes several times a day, to work and back and to meetings in between.

In his first few days on the job, he searched on Google for stories about MARTA over the previous six months. “I couldn’t find a single positive article about the agency -- whether it’s TV, newsprint, whatever,” he says. “Just nothing positive. Overwhelmingly negative. Including my hiring.” His near-unanimous selection was under scrutiny because of open-meeting concerns. “Even that turned into just a negative story for MARTA,” Parker recalls. “So I viewed that as a major thing to work through: how we change the image of the agency.”

Early on, he quickly became aware of just how bad MARTA’s finances really were. The chief financial officer showed Parker a chart with budget projections for the next several years. For the current year, the chart included an anticipated deficit of $25 million to $33 million. It showed similar-sized deficits every year for the foreseeable future. The agency kept dipping into its reserves to bail out annual budgets. Only twice in the last 15 years had it ended up in the black. As of 2012, MARTA was down to $120 million in reserves. In other words, in four or five years, the agency would be financially insolvent.

Parker listened to all the suggestions he could on how to save money, in small or large amounts. The KPMG audit said the agency spent too much on human resources, so Parker asked the department how to cut costs. Employees suggested switching to electronic pay stubs instead of paper ones. The change made MARTA employees happy, and it saved $250,000 a year.

More important from a fiscal standpoint, Parker slashed the agency’s use of outside technology consultants and brought the work in-house. That saved $14 million a year. He pushed for the conversion of the remaining 30 percent of the bus fleet that ran on diesel to natural gas. Natural gas costs roughly a quarter as much as diesel, so the switch saved $5 million a year. All told, rather than losing as much as $33 million his first year, as projected, MARTA closed the books with a $9 million surplus.

Parker made sure the Wall Street rating agencies were paying attention. He visited New York to tout the agency’s accomplishments, and, shortly afterward, Moody’s upgraded MARTA’s credit rating. That, in turn, helped MARTA save $4.2 million on a bond offering.

As MARTA found savings, it worked to lure customers back to the system with better service. Ridership was and is an enormous problem for the transit system. Only 3 percent of commuters in the Atlanta region used public transportation in 2011. MARTA ridership declined by more than 4 percent a year for the four years prior to Parker’s arrival, even as transit systems in other cities were gaining customers.

Parker managed to reduce the wait times between trains from 15 minutes to 10 minutes. He hired bus drivers and reopened bathrooms. Last year, MARTA gave bonuses to employees who had not had a raise in seven years. In Parker’s first year, the agency still lost ridership, but the drop was much smaller, 0.3 percent.

Some of the changes under Parker, though, have involved much more substantial long-term investment. There is a push to start five new transit-oriented development projects on MARTA land by the end of 2014. The idea is to transform the area around existing rail stations. Developers would replace surface parking lots with mixed-use projects featuring residences, restaurants, retail shops and office space. MARTA would lease, rather than sell, the land, which would give it another stream of income. These projects have the potential to benefit the neighborhoods and draw more riders to MARTA.

Other experiments involve smaller issues but ones highly visible to anybody who rides the system. The agency has tried to attract customers by addressing their concerns about safety. Most of the safety complaints involve relatively small nuisances that make the experience of riding MARTA uncomfortable, like persistent panhandlers asking for money, passengers blasting their music or rowdy teens fighting with one another. So Parker started what he calls a “no knucklehead behavior” campaign (its official title is “Ride With Respect”). The agency began cracking down last November on passengers who violated its new code of conduct. It added police officers and had them wear bright yellow clothes to make them more visible. So far, some 1,000 passengers have been suspended -- some for a few days, others permanently.

MARTA aired TV ads promoting the effort to change its image. In the ads, rapper Ludacris says he likes to play his music loud -- but not on MARTA light rail and buses. Comedian Jeff Foxworthy cracks that he likes the system better, now that some of his cousins aren’t allowed to ride.

All of these efforts have led some state officials to see the transit agency in a different light. In the early months, despite MARTA’s mounting deficits, Parker asked for very little from state officials. He did not seek a financial bailout. He only asked that state officials not pass any onerous new laws that could tie the agency’s hands as it tried to prove its merit.

This was all a refreshing change for Jacobs, the Republican chairman of the state oversight panel. Historically, MARTA’s relationship with the state legislature had been a rocky one. Jacobs recalls MARTA and its union, under Parker’s predecessor, painting a third of its buses and trains with red X’s to signify the cuts MARTA would have to make if the state refused to help. The public shaming, Jacobs says, was “exactly the wrong approach to take with the legislature.” Parker has avoided those kinds of tactics. “Those two approaches are very different,” Jacobs says. “One was a bomb-throwing approach that was accompanied by no substantive changes in MARTA’s operations. The other is a very personal type that is accompanied by substantive changes. What’s not to like?”

From the beginning, though, transit advocates wanted Parker to put pressure on state legislators to support the agency, but the transit chief thought that was poor strategy. “It’s like we’d be begging,” he says. He urged them to wait until the agency got its own house in order first. “Then, when we go and talk to [legislators], it’s not asking for money, it’s asking for investment, because we are a strong group, worthy of investment. It’s a whole different conversation than going in with a position of total weakness.”

A year after Parker’s appointment, Jacobs wrote an op-ed column for The Atlanta Journal-Constitution admitting that he had been wrong to protest the selection. Parker is the fifth MARTA general manager Jacobs has worked with in 10 years as its legislative watchdog. “The legislature and MARTA, a state-created authority, historically have had a chilly relationship,” Jacobs wrote. “Listen closely, however, and you will hear the dripping of thawing ice.”

The thaw goes well beyond rhetoric. In the past, Jacobs has pressed MARTA to privatize some of its services, something the agency didn’t want to be forced to do. This year Jacobs pushed successfully for changes that MARTA wanted: a temporary reprieve from restrictions on how it can spend sales tax revenues; clearance to enter into public-private partnerships more easily; and permission to fine, rather than just suspend, customers who violate its rules. The legislation also cleared the way for a potential expansion, the first in the agency’s history, to the suburbs of Clayton County, south of Atlanta.

The only public transportation in Clayton right now is a single MARTA rail stop at Hartsfield-Jackson Atlanta International Airport. The county commission disbanded its bus transit agency in 2010 because the money for the system ran dry. That decision led to a political backlash, and pro-transit commissioners took control.

This summer, the commissioners in Clayton agreed to ask voters to impose a 1-cent sales tax and join MARTA. Transit backers are optimistic the measure will prevail at the polls next month; a nonbinding referendum on essentially the same question in 2010 received 70 percent support.

If the ballot measure passes, MARTA would begin bus service next spring and start work on the Atlanta region’s first commuter rail line (or some other high-capacity option). In addition to bringing thousands of new riders and millions more dollars into the MARTA system, the effort could show other communities that the transit system is equipped to handle further expansions in the future. “Clayton County is important in its own right, but it’s also important because this is our first expansion opportunity in a generation,” says Parker. “We want to send a real clear message to our other potential partners that, you join us, you’re going to get a great value for your money.”

“It’s huge from our perspective,” agrees Doug Hooker, executive director of the Atlanta Regional Commission. “I think we will look back to the time that Clayton County had the referendum on accepting MARTA and say, ‘That was the moment that really began to have the region rethink its relationship with MARTA.’”

Meaningful regional cooperation is still a long distance away. Cobb and Gwinnett counties, two giant suburban areas originally included in designs for MARTA, show no signs of wanting to join. In fact, when the Atlanta Braves announced last year they would build a new baseball stadium in Cobb County, the team and local officials pointedly did not include any plans to make the stadium accessible by any kind of transit. Several more suburban counties lie beyond MARTA’s intended footprint, further complicating efforts to build a regional transit system.

MARTA faces significant challenges on its own, too. State financial support looms as elusive as ever, and ridership, while leveling off, has yet to increase after the recession.

Still, MARTA and Parker have plenty of ambitious plans for the future. There are three major route expansions on the drawing board, waiting for the money and the political consensus to make them a reality. Area transit agencies, including MARTA, are working to integrate their systems so passengers would barely notice when they move from one agency’s vehicles to another’s. And there are still plenty of skeptics to win over.

“We’re doing really good things,” says MARTA Board Chairman Robert Ashe III. “But that’s a justification to do more of it, not an excuse to take our foot off the gas pedal. A friend of mine in the military likes to say your reward for taking this hill is that you get to take a few more hills. That’s the reward Mr. Parker’s going to get.”