Crowded Skies: OAG Reveals the World’s Busiest Routes are in the Asia Pacific

South Korea Jeju (CJU) to Seoul (GMP) is the busiest route on the planet; Kuala Lumpur (KUL) to Singapore (SIN) named world’s busiest international route for a second straight year. Key findings: 1. Kuala Lumpur (KUL) to Singapore (SIN) is the busiest international route in the world with 30,187….