Pittsburgh International Airport is set for a major overhaul, with plans to spend $1.1 billion on transforming it into a facility that is fit for purpose and not based on the way it was in the past.

In 1987, Pittsburgh was a major, growing hub for then USAir, which later became US Airways. At the airline's request, and with their funding, a revolutionary new terminal concept was built and opened in 1992. It incorporated both landside and airside terminal buildings, eliminating the need for connecting passengers to transit security screening more than once. In addition, the large, open structure was a far cry from the old Pittsburgh terminal and the cramped terminals found at airports around the country.

At its peak in 1997, Pittsburgh handled 21 million passengers, and its terminal had the capacity to handle many more. Yet the decline of US Airways and its eventual mergers with America West and American Airlines led to it reducing its hub here significantly.

Today, only a handful of cities are served by American, and other airlines have failed to make up the difference as the airport has struggled to find a new identity. The airport handled 8.3 million passengers in 2016, yet with seeds of growth sown by carriers such as Spirit, Condor and WOW Air in recent month, the airport hopes the tide is turning.

Now, the Allegheny County Airport Authority has announced the intention to remodel the airport's terminal and make it fit for purpose, allowing it to reduce long-term costs and align the facility with the needs of a modern passenger experience.

Central to the overhaul will be the construction of a new landside section of the terminal that will be directly constructed onto the airside satellite terminal, giving direct access from road to gate. It will deal with areas where the existing terminal is too big, reducing the number of gates in the A and B concourses down from 75 to a manageable 51.

It will also address areas where the terminal is currently stretched, including the construction of a new parking garage and roadway, and the elimination of the underground people mover train, which costs $3 million a year to run and maintain.

"You're going to see a single concourse level — with everything on the same level: baggage, check-in, meet and greet," said Christina Cassotis, Allegheny County Airport Authority CEO in a press briefing to announce the overhaul.

The new terminal will have capability of handling 18 million passengers per year, which is more in line with realistic expectations.

The work will be paid for by airport and shale gas revenues, plus floating bonds, and not local tax money. It will bring down the costs of running PIT by around $23 million per year, and airline charges should be reduced as a result.

The time is right to undertake the work as most of the $900 million loans taken to build the existing terminal 25 years ago will finally be paid off next year. The existing landside air terminal could be redeveloped or demolished, as the Authority is keen to open up airport land to developers, which could bring in more revenue.

"We could either be very interested in seeing if a developer is interesting in using this building and rehabbing it ... or it could come down," Cassotis said.

Officials expect to break ground on the project in in 2019 with anticipated completion in 2023.