In 2024, several domestic routes in the United States were notable for their high seat availability and frequency of flights. The four busiest routes by seat availability were Atlanta to Orlando, Honolulu to Kahului, Las Vegas to Los Angeles, and Denver to Phoenix.
The Atlanta-Orlando route offered nearly 3.5 million seats throughout the year. Delta Air Lines dominated this route with more than 10,920 flights and over 2.2 million seats available. Other airlines operating on this route included Southwest Airlines, Frontier Airlines, and Spirit Airlines.
The Honolulu-Kahului route saw a significant number of flights with Hawaiian Airlines and Southwest Airlines as operators. This island-hopper route had over 3.3 million seats available in 2024. Hawaiian Airlines led with more than 15,000 flights scheduled compared to Southwest's over 8,000 flights.