Leaving with two friends for Yosemite National Park today to climb 8,846-foot Half Dome on Sunday, Kim Withrow of San Jose was more worried about the roads on the trip home than on the way out.

“I have a feeling the trip back is going to be a bit hellish,” said Withrow, 58, who works for a Silicon Valley cloud-computing company. “We’re going to be sore and probably sitting in traffic.”

Record numbers of Californians are expected to take to the roads and skies this weekend for the Memorial Day holiday, leading to congested highways and busy airport terminals and parking lots.

Nearly 6 million people from California were expected to travel at least 50 miles from home between Thursday and Monday, a 4% increase over last year and a record for the state, AAA predicted.

Caltrans spokesman Jeff Weiss said road trippers who have to use Interstate 80 and Interstate 880, and Highway 101 and Highway 17 would do well to travel those routes early.

“The peak hours are going to be on Friday afternoon and Monday afternoon and evening,” Weiss said. “We’re expecting an uptick in traffic because that’s been the trend. It’s going to be like the pre-COVID days.”

Those with flexible schedules could avoid traffic by leaving for trips early today and returning early Monday or on Tuesday.

“You’re starting to get traffic in the mid-afternoon that becomes pretty heavy,” Weiss said. “Before, that was a pretty opportune time to beat at least the initial push.”

Roadwork in the Sacramento area could slow travel, “so be prepared for that if you’re going all the way to Tahoe or going to Sacramento,” Weiss said.

Nationwide, today is expected to bring extra-busy roads, especially from noon to 8 p.m., according to AAA.

Some good Memorial Day holiday news for U.S. road travelers came from AAA, which reported Thursday that the national average price for a gallon of regular gas had not risen over last week’s cost.

“Gas prices haven’t been this low over Memorial Day since 2021,” AAA said.

California, however, had the highest gas costs in the country as of Thursday, at $4.87 a gallon, with the national average at $3.19, according to AAA.

AAA said it expected 622,000 Californians would take to the skies around the Memorial Day weekend. Local airports were anticipating high volumes of travelers.

“We’re projecting a busy airport, busy parking lots,” said San Jose Mineta International Airport spokeswoman Julie Jarratt, who noted that Pizza My Heart, founded in Capitola Village, just opened an outlet in Terminal A, and that Willard, the airport’s new golden retriever therapy dog, will be available for cuddles Monday afternoon in terminals A and B.

Historically, the Thursday and Friday before Memorial Day are usually the busiest around the holiday at San Jose International, Jarratt said.

“Every day over the next seven to nine days will be busy, but interestingly enough, it is oftentimes the Thursday and Friday after Memorial Day that tend to be the third and fourth busiest,” Jarratt said.

Jarratt advised travelers flying out of San Jose to book parking online ahead of time.

At San Francisco International Airport, spokesman Doug Yakel had the same advice, with added urgency.

“We’re worried about our parking garages reaching capacity,” Yakel said. Llong-term parking was the most likely to fill up.

The lots at San Jose’s airport were not expected to hit capacity, Jarratt said, adding that travelers can check the status of lots online on the airport’s website.

San Francisco’s airport was predicting more than 600,000 people would fly in and out from today through Monday, with today seeing the most volume.

“Monday will be busy, but more for arrivals — people coming back into town,” Yakel said.

Air travelers should get to the San Jose and San Francisco airports two hours before domestic flights, and three hours before international trips, officials said. Travelers were advised to check in and pay for any bags online ahead of trips to speed their departures.

Officials at both airports warned that those with domestic flights should make sure they have a REAL ID-compliant state drivers license or identification card. The Transportation Security Administration has not started a full crackdown on travelers without REAL ID, but those without one or a passport may face delays for identity is verification.

“The question on everybody’s mind is, ‘When does the hard enforcement come?’ and we have not heard anything about a specific date for that,” Yakel said. He advised people traveling with an identity document other than a REAL ID or passport to arrive at the airport 20 or 30 minutes earlier than otherwise, for identify verification by TSA.

Yakel said he expected significant traffic congestion outside the San Francisco airport’s arrivals area on Monday, as friends and family pick up travelers.

“The one hack is if you are arriving back at SFO and someone is picking you up, go up one level — have them pick you up on the departures level,” Yakel said. “It should be a lot quieter.”

For road travel, AAA and Caltrans both advised a light foot on the gas pedal.

For most cars, fuel economy peaks around 50 mph, AAA said.

“Reducing highway speeds by 5 to 10 mph can increase fuel economy by as much as 14%,” AAA said.

Caltrans’ Weiss highlighted safety reasons for avoiding speeding.

“You’re not saving much time,” Weiss said. “You’re decreasing safety for yourself and others and the advantages are minimal.”

Drivers not taking safety seriously were a primary reason San Jose’s Shawn Overstreet delayed his four-day bicycle trip down the coast from San Francisco to the Watsonville area and back up via the Santa Cruz Mountains until after the Memorial Day weekend. He’ll leave Tuesday, he said.

“I don’t want to ride when all the crazy drunk people are on the highway,” said the 64-year-old former botanical garden curator.