In 2017, airlines moved over four billion passengers, a number that continues to grow each year.

As more and more people around the world can afford to scratch their travel itch, new connections and airports will be created to meet that demand. Remarkably, the world’s air transport network doubles in size every 15 years, and the International Civil Aviation Organisation (ICAO) estimates that it will do so again by the year 2030.

Today’s data visualization – created by researcher, Martin Grandjean – is a dramatic look at over 3,200 air traffic hubs that connect our world’s population centers. The unique, force-directed layout allows us to see relationships beyond geographical location.

These are the air traffic connections between 3,200 airports.
Image: Visual Capitalist

As the GIF above reveals, Europe remains an important linchpin in international travel, and cities on North America’s West Coast – such as Vancouver and San Francisco – swing in response to Asia’s gravitational pull.

The world's most connected airports

While all airports are effective at moving passengers from point A to B, particular locations play a crucial role in the global network. To help put this connectivity between airports into perspective, OAG created the Megahubs International Index.

You can see the top 50 internationally connected airports here.

The heavyweight airport leading the world in international connectivity is London Heathrow. This busy air traffic hub recently had a mind-blowing 72,000 possible international connections within a 6-hour window of arriving and departing flights. Heathrow moved over 78 million passengers and 1.70 million metric tonnes of cargo in 2017.

Air travel connections, visualised.
Image: Martin Grandjean via Visual Capitalist

According to OAG, Singapore Changi and El Dorado International Airport in Colombia were the most connected airports in Asia–Pacific and South America, respectively. O. R. Tambo International Airport near Johannesburg was the sole African airport to crack the top 50.

America's most connected airports

You can see the top 25 most connected airports in the United States here:

While Atlanta Airport, the second most connected hub, has more scheduled domestic capacity, O’Hare’s scheduling offered more connection possibilities for passengers. Both these powerhouse transport nodes show up very clearly on the network map above.

No fly zones

There is a grand total of five countries in the world that have no airport and, interestingly, they’re all in Europe. Vatican City and Monaco are simply too small to accommodate an airport.

The remaining three – Andorra, San Marino, and Liechtenstein – rely on neighboring countries and/or helicopter pads for their air travel needs.