AAA predicts some 112.5 million people (nearly one-third of the U.S. population) will hit the road this holiday season. That represents a 4.4% increase over 2017 and is the highest number AAA has ever expected to travel during the holiday season.

As usual, the majority of the holiday travel will be on the roads, with some 102 million people taking to their cars. That’s going to mean major congestion and AAA expects that the busiest cities, like Atlanta, could see travel times up to four times longer than usual.

The holiday travel season is defined as lasting from Dec. 22 through Jan. 1. As usual, the entire period is going to be super busy but AAA expects Thursday, Dec. 20. to be the worst day to travel on the roads. So if you don’t like traffic jams and crowded rest areas, maybe think about rescheduling.

Airports are hardly going to be empty either. It’s expected that 6.7 million people will take to the skies, which is a 4.2% increase over 2017 and the highest number in 15 years. Should the U.S. government suffer a partial shutdown ahead of the travel season, air travelers can also expect some significant delays.

Yet the there is some good news for holiday travelers. Gas prices are at their lowest averages of the year right now, coming in at $2.46 for the first week of December, two cents per gallon less than the same time a year ago. So if you’re going to fill up, fill it to the top.

Planning on hitting the road? Here are the worst days and times for some big city destinations:

Atlanta – Dec 22 (3-4pm)

New York City – Dec 20 (9-10:30pm)

Boston – Dec 19 (3:30-4:30pm)

Houston – Dec 19 (12:15-1:15pm)

Detroit – Dec 24 (2-3pm)

Seattle – Dec 19 (4-6pm)

Chicago – Dec 24 (1:30-2:30pm)

Los Angeles – Dec 20 (2:30-3:30pm)

San Francisco – Dec 21 (4:15-5:15pm)

Washington, DC – Dec 20 (1:15-2:15pm)