Paris top connecting hub for world flights

WASHINGTON – The city of light is the city of flight, says a new study listing Paris as the most vital connecting point for international air travel.

Anchorage, Alaska, places second on the list followed by London, Singapore and New York.

Connections among 3,883 communities with airports were analyzed by researchers led by Luis Amaral of Northwestern University. The results are published in today’s issue of Proceedings of the National Academy of Science.

The findings are important in understanding the flow of travelers and in studying the potential movement of new diseases, Amaral said. The analysis also may help regulators determine airports where more competition is needed.

A traveler can get from any of the cities to any other with an average of 4.4 flights, and more than half the communities are connected with four flights or fewer, the researchers found. Most difficult route? Getting from Mount Pleasant, Falkland Islands, to Wasu, Papua-New Guinea, requires 15 flights.

The researchers found that the busiest locations are not always the most important for the network. Anchorage, for example, has nonstop flights to 39 other cities, fewer than the 242 cities connected to London nonstop.

But Anchorage edges London in centrality – a rating of shortest paths connecting any two cities that involve a transfer at a particular city. It’s centrality that boosts the importance of cities such as Anchorage and Port Moresby, Papua-New Guinea, which serve as connection hubs.

Alaska has many airports, but most connect only to other Alaskan airports. Only a few connect to the “lower 48” states. There are constraints on flights directly between most of Alaska and Canada. So getting somewhere else may involve going via Anchorage, boosting its centrality rating.

The two busiest U.S. airports are in Chicago and Atlanta. The study ranked Chicago 13th on centrality and 6th for nonstop flights. Atlanta ranked 29th for centrality and 8th in connections.