More than 23 million holiday fliers are expected to pay a record $240 million in U.S. air travel user taxes during the Christmas-New Year period, a trade group said.

Peak travel days will be Friday and Saturday, Dec. 21 and 22, with more than 1.6 million passengers traveling each day, and Tuesday and Wednesday, Jan. 1 and 2, when about 1.5 million daily passengers are expected, according to the Partnership for Improved Air Travel, an association of air travel businesses. The holiday travel period begins on Dec. 19 and ends on Jan. 4, according to the group.A 25 percent increase in user taxes for the Aviation Trust Fund went into effect on Dec. 1. This included a 10 percent increase in the airline ticket tax.

Airline passengers, private pilots and business aviation and air cargo shippers will pay about $5 billion a year for user-financed airport improvements, the association said. The association is pushing such improvements to reduce air traffic delays and airport congestion.

It uses the annual surge in holiday air travel to illustrate what it says are the limits of the current aviation infrastructure to handle higher volumes of passengers predicted as a daily occurrence a decade from now.