AAA predicts that drivers will hit the highways in droves this Memorial Day weekend, lured by low gas prices.

The national average of U.S. retail gasoline prices dropped to $2.24 per gallon today, down nearly 40 percent from $3.71 per gallon a year ago, AAA said.

Trips by automobile will increase 2.7 percent, from 26.3 million last year, to 27 million this year. In contrast, trips by air will decrease 1 percent, with 2.1 million air travelers this year.

About 32.4 million Americans are expected to travel 50 miles or more away from home during the three-day weekend that ends on Monday, May 25. About 31.9 million traveled that distance last year.