Three of the world’s most popular air routes, based on daily flights and the volume of passengers, are Sao Paulo to Rio de Janerio in Brazil, Seoul to Jeju in South Korea, and Johannesburg to Cape Town in South Africa, as of 2015. The busiest route by seats is Seoul-Jeju and by flights a day is San Paulo-Rio. Asia boasts the most routes on the list, and 8.2 million people fly the distance between Tokyo to Sapporo each year.
Over 7.7 million people make the trip to Rio each year from Sao Paulo, making it the biggest tourist draw in Brazil. During Carnival, over 1 million visitors fill the streets of the city, generating about $1 billion in revenue for the local economy.
The trip from Seoul to Jeju holds a record for the busiest route in a single day -- at one point, 94 flights made the hour flight in 24 hours, according to the Huffington Post. Jeju’s luxury hotels are havens for high rollers from Seoul, who head to town for the casinos and nightlife.
In Africa, 4.4 million people fly back and forth between Johannesburg and Cape Town, making it the 10th busiest route in the world, notes Flights.com. In addition, Johannesburg’s airport is the busiest on the continent, as it is a hub between the economic center and Cape town.