By SAM SWEENEY, ABC News

(ATLANTA) — Despite an explosion in COVID-19 cases nationwide and warnings from the Centers for Disease Control and Prevention, more than four million people have passed through TSA screening checkpoints in the four days since last Friday.

According to TSA data, this is the busiest stretch of travel since the pandemic began in March, but air travel is still down nearly 60% compared to last year.

AAA predicts 84.5 million Americans will travel between Dec. 23 and Jan. 3, a 29% decrease from last year.

“While Thanksgiving is traditionally spent gathering with friends and family, the year-end holidays are when Americans often venture out for longer, more elaborate vacations. That will not be the case this year,” said Paula Twidale, senior vice president of AAA Travel. “Public health concerns, official guidance not to travel, and an overall decline in consumer sentiment have encouraged the vast majority of Americans to stay home for the holidays.”

If you are traveling, the CDC has a new search tool that allows users to enter a zip code and find destination-specific information.

The site shows local quarantine rules, testing requirements, and the operating status of local businesses.

“Travel can increase your chance of spreading and getting COVID-19. Postponing travel and staying home is the best way to protect yourself and others from COVID-19,” a CDC advisory explained. “You and your travel companions (including children) may feel well and not have any symptoms, but you can still spread COVID-19 to family, friends, and community after travel.”

President-elect Joe Biden has repeatedly advised Americans against traveling during the holidays.

Travel app Hopper says the top destinations this year for Americans are Atlanta, Denver, Dallas, Austin, and Columbus, Ohio.

American Airlines says its December schedule is approximately 50% smaller than the same time-period last year.

The carrier expects the busiest travel days to be Dec. 21 through Dec. 23, Dec. 27 through the Dec. 30, and the first weekend of 2021.

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