NEW YORK, NY - MAY 24: People wait in a security line operated by the Transportation Security Administration (TSA) at John F. Kennedy (JFK) Airport on May 24, 2016 in New York, New York. The TSA has come under renewed criticism from government officials and the general public following an escalation of wait times at security screenings at domestic airports as the summer travel season begins. Kelly Hoggan, the Transportation Security Administration's head of security operations, has been put on paid administrative leave pending reassignment. (Photo by Spencer Platt/Getty Images)
NEW YORK, NY - MAY 24: People wait in a security line operated by the Transportation Security Administration (TSA) at John F. Kennedy (JFK) Airport on May 24, 2016 in New York, New York. The TSA has come under renewed criticism from government officials and the general public following an escalation of wait times at security screenings at domestic airports as the summer travel season begins. Kelly Hoggan, the Transportation Security Administration's head of security operations, has been put on paid administrative leave pending reassignment. (Photo by Spencer Platt/Getty Images)
Spencer Platt/Getty Images
CNN  — 

A record-breaking 112.5 million Americans will travel during the December holiday season, a 4.4% increase over last year, according to AAA predictions.

That’s more than one-third of all Americans who will be traveling, and it’s the highest number since AAA has been tracking holiday travel.

For the more than 102 million people who are driving, global mobility analytics company INRIX estimates that travel times in the busiest US cities could be as much as four times longer than normal. Those cities include New York City, Washington, Atlanta, Los Angeles, Seattle and Chicago.

” ‘Tis the season for holiday travel, and more Americans than ever will journey to spend time with friends and family or choose to take a vacation,” said Bryan Shilling, managing director of AAA Travel products and services, in a statement.

“With a record-breaking one-third of the country choosing to travel this holiday, roadways and airports are sure to be busy.”

AAA says the holiday travel period starts Saturday, December 22, 2018, and ends Tuesday, January 1, 2019.

A busy flying season

Nearly 46 million passengers will travel on US airlines during the airlines’ holiday period, a 5.2% increase over 2017, according to Airlines for America, the US airline trade group.

The airlines have an expanded definition of that travel time: the 18 days from Thursday, December 20, through Sunday, January 6.

“With airfares at historic lows, travelers are choosing to fly on US airlines in record numbers, especially during the busy holiday season,” A4A Vice President and Chief Economist John Heimlich said in a statement.

Airline etiquette in the not-so-friendly skies

The airlines expect daily passenger volume to range from 2.1 to 2.9 million, with Friday, December 21, Thursday, December 20, and Wednesday, December 26, predicted to be the busiest travel days. Christmas Eve and Christmas Day are expected to be the lightest travel days.