Determined to reclaim Thanksgiving traditions that were put on pause last year by the pandemic, millions of Americans are loading up their cars or piling onto planes to gather again with friends and family.SEE MORE: U.S. Airports Crowded As Holiday Travel ReboundsThe number of air travelers this week is expected to approach or even exceed pre-pandemic levels, and auto club AAA predicts that 48.3 million people will travel at least 50 miles from home over the holiday period, an increase of nearly 4 million over last year despite sharply higher gasoline prices.Many feel emboldened by the fact that nearly 200 million Americans are now fully vaccinated. But it also means brushing aside concerns about a resurgent virus at a time when the U.S. is now averaging nearly 100,000 new infections a day and hospitals in Michigan, Minnesota, Colorado and Arizona are seeing alarming increases in patients.More than 2.2 million travelers streamed through airport checkpoints last Friday, the busiest day since the pandemic devastated travel early last year. From Friday through Tuesday, the number of people flying in the U.S. was more than double the same days last year and less than 9% lower than the same days in 2019.American, Southwest, Delta and United have all been hiring lately, which gives the airlines and industry observers hope that flights will stay on track this week.The airlines have little margin for error right now. American expected to fill more than 90% of its seats with paying customers on Tuesday. That's a throwback to holiday travel before the pandemic.Additional reporting by The Associated Press.