An air-travel information company says Singapore to Kuala Lumpur is the busiest international air route. There were over 30,500 flights between the two cities in one year. That's 84 flights a day, or one every 17 minutes. National and budget airlines fly that route, which takes under an hour. Asia has the top seven busiest international air routes. New York LaGuardia to Toronto, and Dubai to Kuwait were the busiest routes outside of Asia.

The busiest route for passenger numbers was Hong Kong to Taipei. More than 6.5 million people flew this route. Singapore-Jakarta was second, with 4.7 million passengers. The world's busiest domestic air route was Seoul and the Korean island of Jeju. In 2017, 65,000 flights flew that route. That's almost 180 flights a day, or one every seven-and-a-half minutes. The only long-haul route in the top-20 list was New York JFK to London Heathrow.