(NewsNation) — The weekend has proven to be challenging so far for Fourth of July travelers — and the problems persisted on Saturday during a holiday weekend jamming airports with their biggest crowds since the COVID-19 pandemic began.

About 2.49 million passengers went through security checkpoints at U.S. airports Friday, surpassing the previous pandemic-era record of 2.46 million reached earlier in the week, according to figures released Saturday by the Transportation Security Administration.

“We are back to pre-pandemic checkpoint volume,” the TSA tweeted.

The escalating numbers show leisure travelers aren’t being deterred from flying by rising fares, the ongoing spread of COVID-19 or worries about recurring flight delays and cancellations.

With vacationers crowding into airports and on planes, Friday’s passenger volume marked a 13% increase from July 1 last year. Airlines have also spiked their prices to “extraordinarily” high prices, one expert said.

“The airlines made very little money, actually lost money during the pandemic so there is a little bit of probably ‘let’s make up for lost time,'” said Clint Henderson, the managing editor at The Points Guy. “We also have higher fuels costs and higher labor costs, so there’s a bunch of contributing factors.”

In a more telling sign of how close U.S. air travel is reverting to pre-pandemic conditions, an average of 2.33 million passengers have passed through security checkpoints at domestic airports during the seven days ending July 1. That was close to the seven-day average of roughly 2.38 million passengers during the same 2019 period, according to the TSA.

But airlines have struggled to keep up with the surging demand amid staffing shortages and an assortment of other issues that have resulted in recurring waves of flight delays and cancellations that have been transforming some vacations into nightmarish ordeals.

As of Saturday evening, nearly 4,000 flights had been delayed and more than 600 had been canceled at U.S. airports, per flight-tracking website FlightAware.

Pilots say they’re working longer hours and facing fatigue, leading hundreds from Delta Air Lines to protest, seeking better pay and improved schedules.

Travelers, for their part, have reported exasperating flight delays and cancellations that have transformed some people’s vacations into nightmarish ordeals. They’ve also paid higher prices for tickets driven up by soaring fuel costs and other inflationary measures.

Several airlines trimmed summer schedules. Delta even offered passengers $10,000 to give up their seat on a flight recently.

Travel experts are warning: if you’re getting on a plane, have your Plans A, B and C ready to go. Another good rule of thumb is to download the airline’s app on your cellphone and you can work on rescheduling any potentially canceled flights right from your phone.

“It’s a high-stress time for everyone, pilots, flight attendants,” Clint Henderson, managing editor of news at travel website The Points Guy, said.

And it’s not just air travel, as more than 48 million people are expected to travel at least 50 miles or more from home over the holiday weekend, 42 million of those people are expected to travel by car, according to AAA.

“Maybe people are changing their vacation style right now because everything is so much more expensive,” said AAA spokesperson Andrew Gross. “Folks have had a year to watch the airline woes with delays, and cancelations and the long lines and maybe thinking ‘you know I’ve only got five days to get away, I might as well just go by car.'”

Even car travel is expected to set a record, despite the national average price for a gallon of gas being around $5 — or even $6 in California.