OAG has released the details of the busiest routes in the world in 2024, and the US has been very busy. Across the top 10 busiest routes, more than 30 million seats were offered by airlines over the year.
The busiest route in the USA in 2024 is between Atlanta (ATL) and Orlando (MCO) with just short of 3.5 million seats offered. The route has risen to the top spot, beating last year’s busiest route – Honolulu (HNL) to Kahului (OGG) in Hawaii – by around 100,000 seats.
The route between ATL and MCO has maintained a similar capacity to 2023, but HNL to OGG has lost 7% of its seats. Nevertheless, it remains 17% higher than pre-pandemic capacity in 2019.
Also of note is the meteoric rise of the route between New York La Guardia (LGA) and Chicago O’Hare (ORD). Last year it wasn’t in the top 10 at all. This year, it has grown by 17% to take 7th place in the list.
We count down the top 10 routes with more detail on each.
10. Denver – Las Vegas: 2,885,378 seats
| DEN-LAS statistics | |
| Length | 627 miles |
| Airlines | Frontier, Southwest, United |
Hopping over the Rocky Mountains, the route from Denver to Las Vegas has secured 10th place in the busiest US routes 2024 list. It fell five places from 5th in 2023, losing just over 100,000 seats in 2024.
There’s plenty of low-cost competition here, with Frontier and Southwest flying multiple services daily. Frontier uses its A320neo family aircraft for the route, while Southwest uses a mix of 737 NG and 737 MAX airplanes.
United almost always flies the 737 on the route, although it has added the new A321neo from December 3, 2024, on one rotation per day.
9. Atlanta – New York La Guardia: 2,918,755 seats
| ATL-LGA statistics | |
| Length | 761 miles |
| Airlines | Frontier, Spirit, Southwest, Delta |
The first of three routes that involve Delta’s hub in Atlanta (ATL), the connection to New York’s La Guardia (LGA) is in 9th place for 2024 with 2.9 million seats. It retains this position from last year, although seats have gone up by around 200,000.
Delta dominates this connection, with around 15 services daily between the cities. Almost all services are with an Airbus A321, although it occasionally deploys other members of the A320 family on the service too.
Also in competition are low-cost competitors Frontier, Southwest, and Spirit. Southwest flies four times per day with its 737s, while Frontier operates just twice daily and Spirit just once per day. During the busy summer months, frequencies from these airlines do increase, but nowhere close to what Delta offers.
8. Atlanta – Fort Lauderdale: 2,998,172 seats
| ATL-FLL statistics | |
| Length | 582 miles |
| Airlines | Frontier, Spirit, Southwest, Delta |
Zipping down from Delta’s hub in Atlanta (ATL) to Fort Lauderdale (FLL) has become easier than ever with airlines providing just short of three million seats in 2024. That capacity earned it 8th place in the top 10 busiest US routes, down one place from 7th in 2023.
Unsurprisingly, Delta is the biggest carrier on the route, with at least a dozen services every day between the cities. Used on the route is its Boeing 757, with 20 first class and 41 Comfort+ seats on board.
Although Spirit is not the biggest airline on this route, the route is its biggest from FLL. In 2024, it offered over 68,000 seats between the cities, 20,000 more than the next biggest (Chicago – 43K and Newark – 45K). Also competing here are Frontier and Southwest, although their operations are much smaller.
7. New York La Guardia – Chicago O’Hare: 3,118,179 seats
| LGA-ORD statistics | |
| Length | 731 miles |
| Airlines | Spirit, Delta, United, American |
Covering just over 700 miles, the route from La Guardia (LGA) to Chicago (ORD) is the 7th busiest in the US for 2024. All of the ‘big three’ airlines fly the route. United has 15 departures per day, Delta has eight, and American has nine. Spirit also flies the route but has just a couple of departures each day.
Of all the US routes, LGA to ORD had the biggest growth in 2024. Compared to 2023, the route grew its capacity by 17% year on year, moving into the top 10 for the first time.
Airlines are clearly prioritizing frequency over capacity on this route, with many of the rotations operated by regional subsidiaries with small Embraer 175s. When the mainline fleet goes out, it’s usually the smallest aircraft – the A319 or 737 for United and American, and the baby A220-100 with Delta.
6. New York JFK – Los Angeles: 3,158,654 seats
| JFK-LAX statistics | |
| Length | 2,470 miles |
| Airlines | Jetblue, American, Delta |
The iconic transcontinental route from New York to Los Angeles would almost certainly be the busiest in the USA if all New York airports were considered. As it stands, the connection from JFK to LAX secures 6th busiest route in 2024 on its own with 3.1 million seats. It’s also the longest route on our list, covering almost 2,500 miles and taking more than five hours to fly.
Only three airlines operate the route – American, JetBlue, and Delta – but each has some tempting offers to snag their share of the traffic. Delta frequently flies the Boeing 767 on the route, most of which are with the 767-300 with Delta One suites on board.
The other airlines don’t take widebodies, but they do up the game with some excellent premium products. JetBlue operates its Mint class on this long route, bringing wide seats and comfort-enhancing amenities to its Airbus A320s.
American Airlines operates the A321T, a uniquely configured A321ceo that includes Flagship First cabins. However, the airline is in the process of removing these and reconfiguring them back to the regular A321 layout. Taking their place will be the A321XLR, of which it has 50 on order, configured with an all-new business class including direct aisle access and doors.
5. Los Angeles – San Francisco: 3,158,918 seats
| LAX-SFO statistics | |
| Length | 338 miles |
| Airlines | Alaska, United, American, Southwest, Frontier |
In fifth place, it’s the popular west coast route from LAX to SFO. An important business route connection, it’s also popular with leisure travelers looking to explore more of California or to hook up with a long-haul flight from one of the international hubs.
Alaska Airlines and United dominate here, with between 10 and 12 services per day each. However, United has more seats on offer, as all its services use the Boeing 737 family of jets. Alaska Airlines throws a 737 MAX in there once a day or so, but most of its services rely on regional jets like the E175, operated by either Skywest or Horizon.
Land-based transfer between the cities is possible, but it’s a drawn-out process. Combinations of Flixbus USA, Greyhound, BART, and Caltrain tend to take around eight hours in total, and driving down the coast, while pleasant, will take up a good six and a half hours of the day.
4. Denver – Phoenix: 3,214,473 seats
| DEN-PHX statistics | |
| Length | 602 miles |
| Airlines | Southwest, Frontier, American, United |
Denver to Phoenix is the fourth busiest route, climbing from 8th position in 2023. It touches important hubs for two of the USA’s biggest airlines. United Airlines has a hub at DEN, and is the largest airline operating there. PHX is a hub for American Airlines. Naturally, both carriers have a significant presence on the route.
Despite this, the biggest airline on the route is undoubtedly Southwest, providing almost 1.5 million of the 3.2 million seats offered in 2024. In comparison, United Airlines offered just over 800,000 seats, almost half that of Southwest.
United has been flying its new Airbus A321neo on the route since December 2024, although only for one rotation per day. Otherwise, it’s a procession of Boeing 737s from United, Southwest and Frontier, with American occasionally using an A320 family jet or an Embraer 175 operated by American Eagle.
3. Las Vegas – Los Angeles: 3,354,849 seats
| LAS-LAX statistics | |
| Length | 236 miles |
| Airlines | Spirit, Frontier, Alaska, United, Southwest, American, Delta |
The route from Los Angeles to Sin City is the third busiest in 2024 and one of the most hotly contested routes on the list. No less than seven airlines fly this route, including all of the big three, making for intense competition and competitive pricing.
Southwest Airlines is the leading carrier on this route, with more than 800,000 seats available during 2024. Delta was the second busiest, scheduling 560,000, and United came in third with 510,000 seats available.
2. Honolulu – Kahului: 3,369,790 seats
| HNL-OGG statistics | |
| Length | 100 miles |
| Airlines | Southwest, Hawaiian |
The second busiest route was the busiest in 2023, but lost 7% of its capacity this year to fall to second place. It’s also the shortest route on the list, covering just 100 miles, but with a vast swathe of the Pacific Ocean between the two airports, alternative options are limited.
With only about a 45-minute ride between the islands, the service operates like a shuttle bus. Hawaiian alone has more than 20 services per day in each direction, with Southwest adding on another dozen or so.
Hawaiian flies the Boeing 717 on the route, whereas Southwest adds the service onto its transpacific flights with its Boeing 737 MAX.
1. Atlanta – Orlando: 3,474,713 seats
| ATL-MCO statistics | |
| Length | 404 miles |
| Airlines | Frontier, Spirit, Southwest, Delta |
The busiest domestic US route in 2024 was between Delta’s sprawling hub at Atlanta and the popular Florida destination of Orlando. Unsurprisingly, Delta has the lion’s share of capacity, with 2.2 million seats provided by this airline alone.
Frontier and Spirit provide decent capacity on the route, although nowhere near the size of Delta. Each provided around half a million seats over the course of 2024. Bringing up the rear is Spirit, which offered around 250,000 seats in 2024.
The only airline operating a widebody on the route is Delta. Although it mostly uses the 757 for the service, a few services each day are operated by its Boeing 767 widebody. This has a full business class including lie flat seats, although how much use you’d get out of them on an hour-and-a-half flight is debatable.
During the busy summer, Delta also deployed its Airbus A350 on the route, the shortest to use this type. Perhaps we’ll see the big Airbus taking this short trip again in the summer of 2025.
There’s one route in North America that’s even busier
Worthy of mention is a route that is even busier than Atlanta to Orlando, but it doesn’t touch the USA. The burgeoning route between Vancouver and Toronto, connecting east Canada with the west, saw a total of 3,498,835 seats offered in 2024, around 15,000 more than ATL-ORD.
| YVR-YYC statistics | |
| Length | 2,079 miles |
| Airlines | Air Canada, Porter Airlines, WestJet, Flair |
At just over 2,000 miles, it’s almost as long as JFK-LAX and sees intense competition among Canadian carriers for the traffic. Air Canada dominates, flying 10 times per day. Most services are narrowbody, with the 737 and A321 featuring, although some peak trips also see the Boeing 777 and 787 deployed on the route.
WestJet and Flair both use the 737 on the route, but for something a bit different, Porter Airlines brings a fleet type that’s still a relative rarity in North America. The Embraer E195-E2 has proven to be a big hit with passengers, particularly given its 2-2 seating layout (no middle seats).
Porter has also been operating it south of the border, where it has been well-received, and this long 4h 30 min flight is the perfect opportunity to put it through its paces.