BALTIMORE, Md. — As Americans kick off the summer travel season, airports nationwide are jammed with long lines.

More than 41.5 million Americans will travel for the Memorial Day weekend, nearly 5 percent more than last year and the most in more than a dozen years, according to AAA.

More than 3 million travelers are expected to fly.

“Today is going to be one of the busiest days,” said Transportation Security Administration spokeswoman Lisa Farbstein, referring to the travel season.

At BWI Marshall Airport in Baltimore, the TSA expects more than 40,000 passengers on Friday alone.

“This will be only the second time in the history of the airport that we’re expecting to screen more than 40,000 people in a day,” Farbstein said.

While Memorial Day gas prices are at their highest point since 2014, airline prices are down.

According to AAA, airfares are 7 percent lower than last Memorial Day, landing at an average price of $168 for a round-trip flight along the top 40 domestic routes.

“A strong economy and growing consumer confidence are giving Americans all the motivation they need,” said Bill Sutherland, a senior vice president with AAA.

Airline passengers are urged to show up at least 2 hours early for domestic flights. For international flights, they should arrive at least 3 hours early.

“It’s really important that you do that,” said TSA officer Christine Johnson. “We cannot rush you to the front of the line.”

Johnson also tells passengers that they can move through security more efficiently by separating any electronics that are larger than a cellphone.

“Make sure they’re in a bin by themselves,” she said. “Don’t cover them up. It’ll just slow you down because we’ll have to pull it and rerun it through the X-ray.”

The TSA said 243 million passengers are projected to pass through security checkpoints nationwide between Memorial Day and Labor Day weekends.