The Christmas and New Year's holiday period is expected to be the busiest on record for both air and road travel, with the Transportation Security Administration anticipating screening nearly 40 million travelers from Dec. 19 to Jan. 2. United and American Airlines are preparing for their busiest days to be Friday, Dec. 20, and Friday, Dec. 27, respectively. The cheapest days to fly are Christmas Eve and Christmas Day, while the most popular Christmas destinations in the U.S. are Las Vegas, New York City, and Orlando, Florida. About 107 million people are forecast to drive to their holiday destinations between Dec. 21 and Jan. 1, with the busiest days for rental car pick-ups being Friday, Dec. 20, and Saturday, Dec. 21.
Source: https://www.goodmorningamerica.com/news/story/holiday-travel-busiest-times-fly-drive-christmas-new-116720686