Sorry, Southwest customers, that seat is now taken.

Southwest Airlines announced Thursday that it is doing away with its policy of allowing passengers to choose their own seats when boarding the plane. The unusual seating model, which at times resembled a high-stakes game of musical chairs plus luggage, was in place for more than 50 years.

The airline did not say when the changes would be made. A representative for the company pointed to an investor relations website, where Southwest said it “will provide more details on its comprehensive plan” in late September and that it expects bookings under the new system will be available in 2025.

Southwest accounts for roughly 70% of the traffic through Baltimore-Washington International Thurgood Marshall Airport, according to the airport. Over the years, many Maryland travelers have boarded the primary-colored planes with fingers crossed and scanned the cabin for a vacant aisle or window seat. The boldest travelers occasionally tried to save spots for their tardy companions.

Southwest said its research indicated that 80% of customers and 86% of potential customers prefer an assigned seat. It was the No. 1 reason customers cited as a reason for choosing another airline over Southwest. The airline also conducted robust operational testing that included live boarding trials as well as more than eight million simulations.

In addition to seating assignments, Southwest’s plans also including a new process for boarding and a premium option for extended legroom. Seats with extended legroom will eventually account for a third of seats across Southwest’s fleet, according to the company.

The airline is also adding overnight flights in five markets including Las Vegas to Baltimore and Orlando; Los Angeles to Baltimore and Nashville; and Phoenix to Baltimore. The first overnight flights are already available for booking and scheduled to land on Valentine’s Day 2025, according to the company.

“Moving to assigned seating and offering premium legroom options will be a transformational change that cuts across almost all aspects of the Company,” Bob Jordan, Southwest’s president and CEO, said in a statement.

Open seating has been part of Southwest Airlines since its beginning, Jordan said, but the company’s “thoughtful and extensive research” told the company it was the right time to change.

Jordan said the carrier has been “building purposefully” toward the change as part of a comprehensive upgrade aimed at increasing revenue and financial performance.

The announcement comes less than a year after the company agreed to new contract terms with its pilots’ union, significantly increasing salaries, retirement contributions and insurance coverage in step with other airlines. This week, the company reported second quarter profits of $367 million, down significantly from the same time last year when it reported profits of $683 million.

Baltimore Banner reporter Daniel Zawodny contributed to this article.