Why are none of the busiest air routes in the world in the USA?

For many, the end of December is a big time to travel. In the US, the Department of Transportation notes that the number long distance trips taken increases by 23% around Christmas. This is less than around Thanksgiving, but still enough to put a strain on transit infrastructure during this period. With so many people travelling in the US not just around the holidays, but on a regular basis you may expect that the busiest air travel routes in the world would be found here. They’re not.
In terms of the numbers of passengers carried, not a single US air route (domestic or international) makes it in to the list of the top busiest routes published by OAG. The numbers presented are based on seat capacity and not passengers flown. However, we believe seat capacity is a key metric.

Busiest, domestic or international routes?

Before we get to the list, there’s another area to look at when it comes to the busiest routes, are they domestic or international? Not only are there more barriers for passengers wanting to fly internationally (think visas and passport control), governments and airlines need to work out agreements that allow passenger carriage to take place. Perhaps unsurprisingly so, the busiest routes in the world by seat capacity are almost all domestic routes.

Why is the US not in the top-10?

Perhaps one of the key reasons why US routes don’t make it in to the top 10 is because the country is so big. While that would probably mean that there is more reason to fly, it also means that there are more options. Many of the routes in the top 10 are in countries that are smaller than the US. Looking at all the major US carriers, they each have multiple hubs spread throughout the country and traffic isn’t funneled into one channel. To get from New York to LA, for instance, you can fly direct, but there are options to connect you in Chicago, Philadelphia, Detroit, Dallas, Denver, Minneapolis, Atlanta, Phoenix, Seattle, and the list goes on. Point to Point air travel isn’t as big in the US as in other countries. Capacity is spread out in the US, and not concentrated. And where there are very frequent connections, the aircraft are usually a lot smaller.