The Allegheny County Airport Authority has begun its search for architect-engineering firms to realize Pittsburgh International Airport’s $1.1-billion terminal modernization program.

Issued on Jan. 25, the request for proposals seeks a design team to build upon preliminary concepts to overhaul and update a 25-year-old facility originally configured to serve as a hub for U.S. Airways. At the time, the configuration of separate landside and airside terminals with an automated people-mover tram system was considered to be a model for comparable airports around the country.

The carrier’s decline and subsequent integration with American Airlines in 2015, coupled with a rapid reshaping of the aviation industry over the past quarter-century, left Pittsburgh with an airport “built for the past,” the authority acknowledged in a September 2017 statement announcing the upgrade program. It called the airport “much too large in some areas and capacity-constrained in others.”

Pittsburgh International Airport currently serves more than 8 million passengers annually on 16 carriers, according to the authority.

Planned for delivery using a design-bid-build approach and bond funding, the modernization program calls for a three-level, 632,000-sq-ft main terminal, containing an expanded security checkpoint, an improved baggage-handling system, and revamped layouts for passenger check-in and international arrivals. The new terminal will be connected to the existing airside terminal, eliminating the need for the tram system. Airside terminal concourses also will undergo refurbishment, adding 12 gates to the 39 currently in operation.

Other features of the program include a six-story, 4,500-space parking garage that also will house rental-car operations; a quick-turnaround facility for rental cars; a ground transportation center; parking; and an internal road network.

The authority expects to choose an architect-engineer by early summer, with a contractor to be selected later. Construction would begin in 2019, with a targeted completion date of 2023. Capital project management specialist R.W. Block Consulting Inc., Orlando, Fla., has been hired to help oversee the program.