O.R Tambo International Airport
O.R Tambo International Airport
JOHANNESBURG - The Cape Town to Johannesburg route is among the Top Ten busiest air routes in 2017 according to UK-based aviation data monitor OAG. 

It came in at ninth position, but the eight routes above it are all shorter than the Cape Town Johannesburg route, so if we limit it to routes above 750 miles (1 200 kilometers) then Cape Town to Johannesburg would be number one with 31,914 departures in 2017.  

The world's busiest route is between the South Korean island of Jeju and the capital of Seoul with 64,991 departures between Jeju and Seoul Gimpo in 2017, or roughly 178 per day. 

The route's popularity comes from tourism rather than business travel and it so popular among Koreans that a domestic flight from Seoul leaves every 15 minutes on average, which is a test for air traffic controllers and pilots. By contrast the Cape Town route has a frequency less than half this amount. 

The route between Melbourne and Sydney in Australia is the second busiest. In 2017, there were 54,519 departures on the 443 mile route between the two Australian cities, while the route between Brisbane and Sydney is just above Cape Town at eighth spot. 

The Mumbai to Delhi route in India comes third with 47,462 departures in 2017, while the short 337 mile hop from Los Angeles to San Francisco is the first American route on the list, coming seventh overall in volume of departures. The shortest route in the Top Ten is that between Rio de Janiero and Sao Paulo in Brazil at only 222 miles, which is in fifth spot. 

What is surprising is that the Cape Town to Johannesburg route beats that between Beijing and Shanghai in China, which is in tenth spot. The busiest international air route is between Hong Kong and Taipei and it had 29,494 departures in 2017, but that failed to make the Top Ten.

The International Air Transport Association (IATA) reported this week that 2017 international passenger traffic rose by 7.9percent in 2017 compared with 2016. 

This was well above the 10-year average annual growth rate of 5.5percent. Capacity rose in 2017 at a slower rate of 6.4percent, which meant that the airplane load factor climbed 1.1 percentage points to 80.6percent. All regions recorded year-over-year (y/y) increases in demand, led by the Asia-Pacific and Latin America regions.