(NewsNation) — As Memorial Day marks the unofficial start of summer, millions of Americans are hitting the roads and skies for one of the busiest travel weekends of the year.

The Transportation Safety Administration reported it screened a record number of passengers ahead of the weekend and the American Automotive Association is also predicting 2024 to be the busiest Memorial Day weekend on the roads in nearly 20 years.

At an O’Hare Airport terminal in Chicago, people were shoulder to shoulder, trying to make their way to kiosks and security in time to catch their flights.

According to NewsNation’s Alex Caprariello, roughly thirty flights were delayed as of late Monday morning, but only one appeared to have been canceled, reflecting some delays facing travelers across the nation.

Those delays are in part related to severe weather that has swept across the country, with devastating tornadoes ripping across communities over the past week.

Delays aren’t stopping travelers, however. The TSA reported 2.9 million travelers on Friday alone, a single-day record. Across the three days, Friday, Saturday and Sunday, there were 7.7 million flyers around the country, over half a million more than the same period of time in 2023.

Road travel is also starting up, with a lot of families opting to drive for convenience, ease of traveling to nearby locations and cost as airline prices have increased.

Road trippers haven’t quite set a record but they have come close, with 43.8 million families on the road over the holiday weekend, which is close to the 44 million record set in 2005. One factor that might be influencing that is gas prices, which are hovering around $3.57 for a gallon of gas across the U.S.