The rise of the omicron variant does not appear to be keeping travelers home for the holidays: More than 2 million passengers a day have passed through Transportation Security Administration checkpoints since Thursday, with even busier days expected ahead.
That leaves the number of people who traveled in 2020, when many stayed home, in the dust. And it means some travelers might be heading out on their first big trip since Christmas 2019.
Here's what those who are returning to the roads and skies - for the first time in years, or even just weeks - should be aware of.
Be extra cautious as omicron spreads
According to data gathered by The Washington Post, new daily cases have risen 23 percent in the past week. Projections from the Centers for Disease Control and Prevention say omicron was responsible for 73 percent of new cases between Dec. 12 and 18.
Chris Beyrer, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, told The Post recently that the surge is "higher and faster than anyone anticipated." Travelers should consider what they would do in case of infection, and decide whether they can afford that risk.
Top infectious-disease specialist Anthony Fauci said Sunday that people who have been vaccinated and boosted "should be OK" to travel, as long as they take precautions, like keeping a mask on in places like airports.
"I think people just need to be prudent," he said. "Clearly when you travel, there is always a risk of increased infection; that just goes with respiratory illnesses."