ST. LOUIS – Southwest Airlines is posting record numbers at St. Louis Lambert International Airport, and its terminal is running out of room.

New numbers make it clear that St. Louis is essentially a Southwest “hub.”  More than any airline, Southwest needs the most space at Lambert.

The airport is launching a westward ground-level expansion of Terminal 2 to add baggage claim capacity for Southwest.

“They have three, four, or five planes arriving at one time, and baggage claim is a mess,” said passenger Jeff Marshall. “If they’re willing to commit to us and expand, then we need to commit to them and give them space to do that.”

Southwest will pay off the estimated $60 million in bond-financing for the project, which is expected to be finished in 2025.  

It is a short-term solution for an airline relying more and more on St. louis. 

Southwest officials say they don’t have traditional “hub” airports, but Lambert is now one of its top “connecting” points with a very “hub”-like market share. 

“If you think about FAA definitions of hub connectivity, anything that exceeds 25% is deemed a connecting hub,” said Lambert Airport Director Rhonda Hamm-Niebruegge.  “[For] Southwest, 35% of their market share is connecting out of here. It’s a strong operation, and it’s continuing to grow.” 

Southwest’s capacity is hitting record levels in St. Louis as well, according to a metric known as ASM, also known as “available seat miles.”

“The number of seats has grown with [Southwest] by 7% come this March, which will be the highest they’ve ever had in St. Louis,” said Hamm-Niebruegge said. “That brings some needs and challenges, part of why we think about what the future looks like and how we accommodate the things that we’re seeing.”

These kinds of numbers are “fuel” in the push for the nearly $3 billion proposed single terminal expansion, which would have a projected completion date of 2031. Hamm-Niebruegge says both St. Louis and Southwest Airlines are going to need it.