The unofficial kickoff to the summer season is upon us — and motorists will be hitting the road, and hopefully with their radios on.

The American Automobile Association (AAA) is warning of potentially unprecedented congestion on roads for the Memorial Day weekend, along with crowded airports. AAA says an estimated 43.8 million people across the U.S. would likely travel at least 50 miles from Thursday (May 23) to Monday (May 27).

AAA says that would be a 4% increase in overall travel vs. 2023. It would also approach the busiest Memorial Day weekend on record, when 44 million people left home in 2005.

“We haven’t seen Memorial Day weekend travel numbers like these in almost 20 years,” Paula Twidale, the Senior VP of AAA’s travel division, said in a statement. “We’re projecting an additional one million travelers this holiday weekend compared to 2019, which not only means we’re exceeding pre-pandemic levels but also signals a very busy summer travel season ahead.”

AAA estimates that 38.4 million people will travel in cars over the course of the weekend. That would be the biggest number recorded around the Memorial Day holiday since the group first started keeping track of Memorial Day travel patterns in 2000.

According to car rental company Hertz, demand for vehicles this year will be highest in Atlanta, Boston, Las Vegas and Orlando. Hertz tells AAA most renters are scheduled to pick up their cars on Thursday and Friday.

Meanwhile, U.S. airports expect another travel spike. An estimated 3.51 million people will fly this weekend, AAA says, up from the 3.35 million who traveled on planes to their destinations last year. That could make for the most crowded Memorial Day weekend at airports since 2005. That year, according to AAA, 3.64 million people caught flights for the holiday.