ST. LOUIS— Travelers passing through St. Louis Lambert International Airport in the coming years could see a dramatically different facility under a $3.4 billion master plan designed to modernize and expand the airport’s capacity without adding new runways.

Airport officials say the long-term plan, published in 2023, calls for replacing the current two-terminal layout with a single, consolidated terminal. The redesign aims to accommodate up to 40 million annual passengers and 500,000 aircraft operations. However, forecasts in the master plan estimate traffic will reach about 21 million passengers and 230,000 aircraft operations annually by 2040, compared with 195,000 operations in 2019.

Roughly $2.8 billion of the total cost is earmarked for terminal reconstruction. The project is expected to be funded through airport and airline revenue, including fees generated from flights and concessions.

City Comptroller Donna Baringer said the existing layout no longer meets the airport’s needs.

“It’s not set up for what it needs to do,” Baringer said. “That put a burden on the airport it could not handle. That’s exactly why we need a new terminal.”

Baringer said travelers can expect improvements in security screening and baggage handling.

“We’re going to have upgrades in getting through security. We’re going to have upgrades in luggage because that’s a big issue right now,” she said.

Air cargo operations are also projected to grow significantly. The airport handled about 75,000 tons of cargo in 2019, and that figure is expected to increase to an average of 102,000 tons annually by 2040.

Tourism officials say the upgrades could also strengthen St. Louis’ appeal as a destination.

“It’s the front door of St. Louis,” said Catherine Neville of Explore St. Louis, referring to the airport’s role in shaping visitors’ first impressions.

The city selected locally based design firm HOK to lead the project. The firm’s previous work includes designs at Chicago’s O’Hare International Airport and New York’s LaGuardia Airport.

“We are thrilled to be collaborating with the City of St. Louis and the team at Lambert International Airport on this transformative project and look forward to sharing our design ideas in the future,” said Eli Hoisington, HOK’s co-CEO and design principal.

The airport’s four existing runways will not be expanded under the plan. Construction is expected to begin this year and continue for five to seven years.

Upgrades to snow-removal and operational facilities began in October to improve reliability during winter weather events, including recent snowfall that dropped about 8 inches across the region.

Airport officials say the goal is to modernize the facility while positioning Lambert for long-term growth in passenger traffic, cargo and tourism.