The largest terminal modernization project in Baltimore-Washington International Airport’s (BWI) history is underway, with new facilities set to open in late 2025—which airport officials say will create room for Southwest Airlines’ continued growth.   

The project, on which construction began this year after final approval in October 2022, will include a two-level structure connecting the airport’s A and B concourses and a new baggage handling system.

The upgrade “primarily provides expanded baggage capacity for Southwest Airlines for their growth plans, but it includes a number of other amenities like expanded hold rooms, restaurants and more concessions,” BWI CEO Ricky Smith told Aviation Week Network on the sidelines of a recent ceremony at the airport celebrating Copa Airlines’ newly launched 4X-weekly service from Panama City’s Tocumen International Airport.

The total cost of the project is pegged at $425 million, with funding coming from the state of Maryland, which owns and operates the airport.

Southwest is the dominant carrier in the Baltimore market, where it stations 4,000 employees. The Dallas-based airline had a 70.2% passenger market share at the airport in April 2023, far outpacing second-place Spirit Airlines (8.4%) and third-place Delta Air Lines (7.3%). BWI is Southwest’s largest U.S. East Coast airport, and airline executives have emphasized its future importance to its network. 

The modernization project “allows us to accommodate that growth,” Smith said, adding the connector will “make it easy to get from one concourse to another ... and enhance the customer's experience altogether. We expect to open up the facilities around December 2025.”

In terms of traffic recovery, BWI reports it handled 2.2 million passengers in April 2023, up 15.2% year-over-year, but still down 1.8% versus April 2019. Aircraft movements at the airport were down 10.9% in April compared to the same month in 2019.

Smith said recent flight delays and cancellations at U.S. East Coast airports “demonstrate that we still have some work to do as an industry, both on the air traffic control side as well as on issues like the pilot shortage.” He added U.S. airlines and airports are “going to be working through [strains on the system] for probably the balance of the year. But for the most part, air travel is reliable and safe.”

Separately, Southwest and BWI are collaborating on construction of a new $135 million aircraft maintenance facility—a 27-acre site that will include a hangar to accommodate up to three Boeing 737 aircraft. The airline is investing $90 million in the maintenance facility.