Ridership on the AirTrain that takes passengers to Kennedy Airport has grown nearly 30 percent since 2007, according to the Port Authority.
Passengers on the train, which connects the airport to the Long Island Rail Road and subways at Jamaica station, say convenience and savings on parking fees and gasoline have led them to use the elevated light-rail service.
The 8.1-mile line carried 5.7 million passengers in 2012, up from 4.4 million six years ago. The system, which also serves rental car operations, opened in December 2003.
The AirTrain has become a convenient way for travelers to reach their flight or employees to get to their airport jobs while avoiding traffic congestion on the highways, said Patrick Foye, the authority's executive director.
"It's heavily used by airport employees for getting to work and moving around the airport," he said.
That includes Long Islanders like Cynthia Smith, 26, a Transportation Security Administration employee from Central Islip. She commutes on the Long Island Rail Road to Jamaica station in Queens, where she switches to the AirTrain.
"It's convenient," Smith said while waiting for a train at Jamaica. "You don't have to drive."
While train ridership is up, the number of people who drive to the airport and pay to park is declining and has led to a dip in revenue, Foye said.
Port Authority statistics show that the number of airport users who pay for parking at all of the authority's airports -- Kennedy, LaGuardia and Newark Liberty -- has fallen about 20 percent between 2007 and 2012. Last year, airport customers who paid for parking totaled more than 8.6 million, down from 10.8 million in 2007.
Airport parking at Port Authority lots is $33 for 24 hours. Privately run off-site parking lots offer lower rates.
Foye said the authority is working to increase parking lot usage by marketing the "convenience" of parking at Kennedy Airport.
"We regularly survey parking customers, and have recently completed two other market studies on what our parking customers are looking for," Foye said. "We're working on redesigning our airport parking Web pages. We're in the process of upgrading the market and branding of our airport parking."
Smith said using the AirTrain not only saves her the parking fees, but saves on her gasoline use.
A one-way AirTrain ticket costs $5. Riders of the Metropolitan Transportation Authority's E, J and Z subway lines can connect to the AirTrain at Jamaica, and A train riders can pick it up at Howard Beach.
Occasional shutdowns for maintenance are the only downside of commuting by AirTrain, Smith said.
"There are a lot of issues with delays and maintenance on the track," she said. "You never know when it's going to happen. Sometimes, employees are late because of it."
But Foye said such a heavily traveled light train system is going to need to be taken offline for maintenance. Superstorm Sandy also caused service interruptions. When the train is not in service, shuttle buses are provided, he said.