As Americans slowly return to flying, airlines are dropping some of the changes they made early in the pandemic.

Southwest Airlines has gone back to boarding passengers in lots of 30. During the pandemic, it restricted boarding to 10 passengers at a time to create more space between them.

Airline spokeswoman Brandy King said Wednesday that the change went into effect on March 15. She said that when Southwest started boarding in smaller groups last May, face masks weren’t as common, and people were just getting accustomed to social distancing in public places.

Southwest and several other airlines that once blocked middle seats now sell out flights if they can. The last holdout is Delta Air Lines, which has extended empty middle seats through April 30.

A search of Delta flights in May showed middle seats for sale. A Delta spokesman said the airline hasn’t decided whether to extend the middle-seat ban, and if it does, passengers in middle seats can be moved to window and aisle seats.

Many airlines are also bringing back snacks and drinks after halting service last year to limit contact between flight attendants and passengers. Some, but not all, have resumed selling alcohol —Southwest is still dry; other airlines vary service by flight length and whether passengers are in first-class.

Tuesday marked the 13th straight day that more than 1 million passengers went through U.S. airport checkpoints, according to the Transportation Security Administration. Traffic is still down about half from the same period in 2019, however.