Today Is Not the Busiest Travel Day of the Year

— -- Get ready for long lines at the airport tomorrow.

Or, maybe not.

The commonly held "wisdom" is that the Wednesday before Thanksgiving is the busiest travel day of the year. That's not true, at least when it comes to flying.

"It is not considered one of our 'busy' days," when compared to summer weekends, Airlines for America spokesperson Melanie Hinton told ABC News. Airlines for America is the leading airline industry trade group.

In fact, the Wednesday before Thanksgiving is not even the busiest day of the Thanksgiving travel season -- it's the Sunday after the holiday, said Hinton. Karen May, a spokesperson for United Airlines, said the Wednesday before Thanksgiving is peanuts compared to summer weekends.

Travelers should absolutely leave additional time to get through airport security on Sunday. But the long lines will pale in comparison to the Friday before Memorial Day, the third-busiest travel day of 2014, according to Airlines for America (The second busiest travel day for 2014 was Friday, June 20). Thirteen of the 15 busiest air travel days of the year are during the summer months, between mid-June and early August.

When it comes to cars, the data's not as clear. AAA told ABC News that more drivers will be on the road on the Wednesday before Thanksgiving than the Memorial Day and July 4th holidays.