Hartsfield-Jackson International expects more than 5 million travelers to use the world’s busiest airport over the next three weeks, with some of the the biggest crowds at the end of this week.

The holiday travel period for the airport runs from Dec. 17 until Jan. 6, with surges Thursday, Friday and Saturday, and again Dec. 31-Jan. 2.

Passenger counts at the Atlanta airport were up 3.3 percent for the year through October, on track to top last year’s record of 92.4 million passengers. Just as the holiday period ends, heavy business travel is set to resume Jan. 7.

Infrequent fliers may notice some changes this holiday season.

Hartsfield-Jackson in May opened a new international terminal, with a separate entrance off I-75 for travelers boarding international flights. The airport continues work on its concessions overhaul. On Saturday, the Atlanta ChopHouse restaurant opened in the domestic terminal atrium in the space previously occupied by Houlihan’s.

Meanwhile, airline passenger traffic counts nationally are expected to be down slightly for the holidays this year. Industry group Airlines for America predicts nearly 42 million passengers will fly from Dec. 17 through Jan. 6, down less than 1 percent.

Planes are expected to average 85 percent full over the period, and could hit 90 percent on the busiest days, the group said. A recovering economy and “air travel that continues to be a bargain” are driving the solid traffic, according to Airlines for America.