The United States Transportation Security Administration (TSA) said it screened 1.63 million people on Sunday at U.S. airports, the highest single-day screening number since March 2020 when the coronavirus pandemic started.
The number of passengers screened on the same day in May of last year was 170,000, according to Reuters.
The TSA said that the air travel industry is down 35 percent compared to the same time in 2019, before the pandemic, with about one million fewer travelers.
Airlines said they are receiving an uptick in bookings as vaccination rates increase, federal mask-wearing guidelines are loosened, and other nations such as those in Europe ease travel restrictions.
United Airlines said last month that the company planned to add 480 daily flights to the U.S. schedule in June, adding to it now 3,100 daily flights. The airline expects the larger amount of vaccinated people will increase summer travel demands.
American Airlines said in April that it planned to add 150 new routes and increase its domestic seat capacity by 90 percent by this summer.