Holiday travel forecast: What to know before hitting the roads or the skies

Americans are gearing up to hit the roads and the skies for the holidays -- and airlines are bracing for a packed travel season.

Here's what you need to know before hitting the road or heading to the airport:

Best, worst days to drive

Nearly 102 million Americans -- 90.4% of travelers -- will drive to their holiday destinations, according to AAA.

The worst days to be on the road are Dec. 23, Dec. 27, Dec. 28 and Jan. 2, according to transportation analytics company INRIX.

But if those are your planned travel days, the best times for motorists are 2 p.m. or earlier and after 8 p.m. The best times on Jan. 2 are before 3 p.m. or after 8 p.m., INRIX said.

The best days to drive are Christmas Day, New Year's Eve and New Year's Day, according to INRIX.

Most expensive and least expensive days to fly

Based on average ticket prices, the most expensive day to leave town for Christmas is Thursday, Dec. 22, followed by Saturday, Dec. 17, and Friday, Dec. 23, according to Expedia.

The cheapest day to fly before Christmas is Dec. 19.

When planning your return trip, avoid flying back on Mon. Dec. 26. Instead, book for Dec. 27 or Dec. 28, according to Expedia.

Looking for the ultimate budget-friendly day? Book a flight for New Year's Eve, according to Expedia, when ticket prices are more than $200 cheaper than average for the holiday period (Dec. 17 to Jan. 1).

Jan. 2 will be United's busiest day

United is planning for more than 8.3 million travelers over the holidays -- about 1.9 million more than last year.

But thanks to remote work, United said the holiday travel period is getting longer and demand is less concentrated on peak days.

Jan. 2 will likely be United's busiest day, when more than 480,000 travelers are expected. The airline said it anticipates setting a new post-pandemic travel record.

Chicago O’Hare will be United's busiest hub, followed by Denver, Newark and Houston, according to the airline.

Dec. 22, Dec. 23 and Dec. 27 peak days for Delta

Delta said it expects about 9 million customers from Dec. 16 to Jan. 3 -- just shy of its 2019 numbers, when the airline had about 9.3 million customers.

Delta’s largest hub, Atlanta, will have more than 800 daily flights on average.

Delta forecasts its peak travel days to be Thursday, Dec. 22, Friday, Dec. 23, and Tuesday, Dec. 27.

Dec. 22 is American's biggest day

American Airlines predicts to see more than 10 million passengers from Dec. 16 to Jan. 2.

American said its busiest day is Dec. 22 with 5,520 departures, followed by Dec. 15 with 5,514 departures.