When the summer travel season begins, airline passengers typically brace for delays as vacationers fly in larger numbers and the inevitable weather-related disruptions occur.

The Federal Aviation Administration, which oversees the nationwide system of air traffic control, is hoping to make some of those delays a thing of the past. It's developing what it calls "Next Generation" technology. The NextGen program will modernize the air traffic control system, transforming it from radar to GPS-based technology.

But as the government works out the details, questions remain about its cost and viability.

Aiming For Efficiency

It's a bright, sunny day at Dallas/Fort Worth International Airport. From the control tower, "we're looking out the window at the east airfield ... where there are four runways that are in active operation," says Michael Huerta, the FAA's acting administrator.

Except it's not really Dallas/Forth Worth. Huerta is in a government lab in New Jersey, looking at a computer-generated simulation.

"What this enables us to simulate is how controllers would use technology to control traffic, in this case at Dallas/Forth Worth airport," he says.

The William J. Hughes Technical Center, located next to the Atlantic City airport, is where the government is developing the NextGen system, including the equipment that air traffic controllers use in towers at airports across the country.

There are hundreds of technicians in the Atlantic City lab working on everything from how to transmit up-to-the-second weather information to pilots to the kinds of equipment or avionics that the airlines will need to install in their jets.

The goal, Huerta says, is an air traffic control system that allows more flights in the sky, better fuel efficiency and more closely spaced takeoffs and landings.

"Right now, conventional descent into an airport looks a lot like walking down the stairs, and a pilot will throttle up, throttle back, throttle up and throttle back. It's the aviation equivalent of stop-and-go driving in traffic, and it's very fuel inefficient," he says. "It also is rather noisy."

Huerta says NextGen allows a smooth, steady glide descent, akin to sliding down the banister. The FAA estimates the new technology will save over 1 billion gallons of fuel and reduce carbon dioxide emissions by 14 million metric tons by 2020.

Getting The Big Picture

At one lab in the complex, new ways of tracking flights are tested by air traffic controllers who are brought in from the field.

Their responses are closely watched by Nick Marzelli. "What we can do is we can train a camera on them and then, as we introduce these anomalies in the system, to see how they're handled by the controllers," he says. "We're sort of recording them. We're recording their voice, if they're bantering about a little bit. We're recording what they're doing ambient-wise."

There is also a cockpit simulator, where pilots can try their hand at the controls of an Airbus jet.

Huerta says the point is to understand how the pilot and the air traffic controller can best share information. With NextGen, pilots will have a better sense of who and what is in the sky around them.

"What we're really trying to understand," Huerta says, through technology like the tower simulator and radar room simulator, is: "How is that whole interface working?"

A Long-Term Proposition

Transitioning from 1940s radar to current-day satellite-based technology isn't cheap.

The cost has been estimated at some $40 billion, to be shared by the government and the airlines. Congress this year agreed to spend some $4 billion over the next four years on NextGen.

But the private sector remains wary, says Joshua Schank, president of the ENO Center, a transportation think tank.

"The private sector is very risk-averse when it comes to making investments that they don't see an immediate return on — particularly the airline industry, which is an industry that has been suffering and really never made money its entire history," Schank says. "For them to go out on a limb and invest in a new technology with questionable benefits — it's just not going to happen."

Still, progress is being made. The FAA and some of the airlines are testing new landing approaches to take advantage of the more efficient technology at a handful of airports, including Seattle-Tacoma and Atlanta's Hartsfield. And NextGen has enabled controllers to track helicopter traffic to and from the Gulf of Mexico's oil rigs for the first time.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.