U.S. highways and airports will be back to near pre-pandemic volumes over the busy end-of-year travel season and public health officials are urging safe practices for both the journey and the holiday celebrations as COVID-19 case counts, driven by the omicron variant, continue to surge.

AAA is predicting nearly 110 million U.S. travelers will be heading out of town from Dec. 23 to Jan. 2, exceeding 2020’s holiday traffic by almost 28 million and coming up just shy of 2019’s pre-pandemic travel flow of 119 million over the same period.

About 6.4 million travelers will get to their holiday destinations via the air. The Salt Lake City International Airport reports it is expecting 25,000-plus departing passengers Wednesday and Thursday, more than double pre-Christmas departures last year.

Travel industry leaders are joining public health experts in imploring all travelers to follow guidance on safe practices and, most importantly, to get vaccinated or boosted.

“With vaccines widely available, conditions are much different and many people feel a greater level of comfort traveling, but travelers will still be mindful of the pandemic and the new omicron variant,” said Aldo Vazquez, AAA Utah spokesperson.

The COVID-19 omicron variant is now accounting for most of the new infections in the U.S. and experts warn the highly communicable strain will heighten risk of illness for airline travelers.

In Wednesday reporting by The Hill, a leading medical adviser to a group representing nearly 300 airlines said in a new interview that aircraft passengers are two or three times more likely to be infected with COVID-19 on a flight since the emergence of the omicron variant.

“Whatever the risk was with delta, we would have to assume the risk would be two to three times greater with omicron, just as we’ve seen in other environments,” Dr. David Powell, physician and medical adviser to the International Air Transport Association, told Bloomberg News.

He added that “it’s just that the relative risk has probably increased, just as the relative risk of going to the supermarket or catching a bus has increased with omicron.”

Air travelers who choose to stage protests on airplanes or at airport facilities, where masks are required, will be facing zero tolerance responses from security personnel under a no-warning policy the Federal Aviation Administration instituted in January. Incidents that escalate to verbal threats or physical assaults of other passengers or airline employees come with penalties that include fines of up to $35,000 and jail time.

And unruly airline passengers may face additional consequences for bad behavior under a new partnership between the Transportation Security Administration and FAA.

Under the partnership, the FAA will share information of passengers facing fines for unruly behavior with TSA which may remove the passenger from TSA PreCheck screening eligibility, which is a privilege reserved for low-risk travelers, according to a posting on the FAA website.

“TSA has zero tolerance for unruly behaviors, especially those involving physical assault occurring aboard aircraft. We have tremendous respect for airport staff, gate agents and flight crews that get people safely to their destinations,” said TSA Administrator David Pekoske. “This partnership with FAA will help ensure the safety and security of all passengers and hold those who violate federal regulations accountable for their actions.”

The Centers for Disease Control and Prevention advises that the best way to minimize COVID-19 risk and keep family members and friends safe is to get vaccinated if you’re eligible.

The CDC also posted this list of guidelines ahead of 2021 holiday travel and celebrations: