Busiest route for international scheduled flights from point-to-point

According to the International Civil Avation Organization (ICAO), the air route between Hong Kong and Taipei, Taiwan, is the world's busiest. In 1999, 3.96 million passengers flew between the two cities. London, UK, to Dublin, Ireland, was second with 3.85 million, and London to New York, USA, was third with 3.82 million.