The world’s largest airports experienced year-over-year passenger growth of 5.5 per cent in 2016, but traffic declined in about one in four airports that handle less than a million passengers annually, according to a new report from the industry group Airports Council International (ACI).

“The downside of airline capacity shifts is that a proportion of smaller regional airports have either stagnated or experienced a reduction in nonstop destinations between cities,” said Angela Gittens, director general of ACI World.

“The reason smaller airports remain in operation hinges on the fact that they contribute to the local, social and economic development of their surrounding communities. Strategies to ensure their sustainability are important if we are to have a robust aviation system.”

The new World Airport Traffic Report noted that Atlanta Hartsfield International Airport remains the busiest domestic airport in the world, with 92.7 million passengers annually (up 2.7 per cent), followed by Beijing and Chicago O’Hare. The busiest international airports were Dubai, London Heathrow and Hong Kong.

Bangalore, Ho Chi Minh, and New Delhi grew the fastest among airports with more than 15 million passengers annually. Airports that topped 40 million passenger for the first time in 2016 included Barcelona, Taipei, Kunming, Sydney, Shenzhen, Orlando, Mexico City, Newark, and Shanghai.

Worldwide, airport passenger traffic increased 6.5 per cent in 2016, to almost 7.7 billion, with all regions experiencing growth except Africa. Traffic in North America rose 3.5 per cent.