Passenger trains could be running again between Camden and Glassboro by 2019, if someone comes up with $1.6 billion and the current construction schedule doesn't slip.

Those are big ifs.

South Jersey residents got an update Monday evening on the latest plans for a long-discussed 18-mile light-rail line that would restore passenger service to a corridor now used only for freight trains.

At a show-and-tell session at Woodbury High School, about 100 area residents talked to officials of STV Inc., the engineering firm conducting an $8.1 million environmental-impact study for the Delaware River Port Authority.

Some were enthusiastic about the prospects of restored rail service to Philadelphia and nearby South Jersey towns. Others were wary of construction, parking and noise that could come along with the railroad.

"It should have been done long ago," said Kevin Berrigan of Woodbury. "It would take cars off the road." Berrigan said he was a big fan of the River Line between Camden and Trenton, which operates much as the proposed Glassboro-Camden line would.

"I'm all for it," said Nora Iwanaga. "I live in Woodbury, and I'd be close to either station . . . I could use it to go to Cooper [hospital] or visit my friend in Pitman."

Sean Kersey, a school bus driver who lives close to the tracks in Woodbury, said he worried about the impact of construction of rail stations and commuter parking.

"Will people be parking all over the community? What about noise? Will people be uprooted? How will it affect the community?" Kersey said.

Preliminary plans call for trains operating every 71/2 minutes during rush hours and every 15 minutes during nonpeak times. Trains would operate until about midnight, and as many as 18,000 daily riders are expected by 2030.

The ongoing environmental study is to examine impacts of noise and vibration, air pollution, social and economic changes, historic preservation efforts, as well as the estimated costs to build and operate the rail line.

A draft version of the study report is to be completed by early spring of 2014, with a final report to be finished by fall of 2014.

"This feeds a decision point, so that stakeholders and decision-makers can make an informed decision as to whether to go forward or not go forward," said STV vice president Joseph F. North.

If approved by the Federal Transit Administration, the environmental impact statement would serve as a blueprint for design and construction of the line, with construction starting in 2016 and operations beginning in the second quarter of 2019, deputy project manager Peter Fedun said.

NJ Transit will pay for the environmental-impact study, and the DRPA will oversee that work. But financing remains elusive for the rail line.

The DRPA has said it would not pay to build or operate the line, and NJ Transit has not committed itself to paying for it either.

The $1.6 billion light-rail line would run alongside a Conrail freight line through Glassboro, Pitman, Mantua, Wenonah, Woodbury, Deptford, West Deptford, Westville, Bellmawr, Brooklawn, Gloucester City, and Camden.

It would connect to PATCO and River Line trains at the Walter Rand Transportation Center in Camden, where passengers could catch trains to Philadelphia or Trenton.

A separate, $800,000 environmental study is underway for a proposed rapid-bus system to serve much of the same corridor.

That $46 million bus system would use a 23-mile main line to Philadelphia from Avondale, in Winslow Township, with a branch that would take riders from Deptford along Route 55 to join the main line at its merger with Route 42.

That yearlong study is being conducted by engineering firm Aecom Technical Services Inc., of Newark, N.J., for NJ Transit.

The rapid-bus service could be in full operation by 2020, with some parts phased in before that. Construction could begin in mid-2014.