It appears that the skies have become increasingly crowded and flights more frequent over the past year, a sentiment particularly resonant for residents of Hong Kong and Taipei. The travel intelligence firm OAG has unveiled its latest annual ranking of the world's most trafficked flight paths, with the 105-minute journey between these two cities securing the top spot on the international routes list, offering nearly 7 million seats in 2024.

The route, which saw 6,781,577 passengers, has regained its pre-pandemic status as the busiest, having also led the charts in 2019. It was ranked third in the previous year's list. In contrast, the top route of the previous year, Singapore-Kuala Lumpur, had a comparatively modest 4.9 million seats available.

Securing the second position on this year's list is the Cairo-Jeddah route, with nearly 5.5 million seats sold. This Egypt-Saudi Arabia connection has experienced remarkable growth over the past half-decade, climbing from the 14th spot in 2019 to second place in both 2023 and 2024. Seoul's Incheon Airport also made a strong showing, with flights to Tokyo Narita and Osaka Kansai taking the third and fourth spots, respectively. Singapore's Changi Airport, which made a significant impact in the 2023 rankings,occupyed it three spots in the top 10, with routes to Kuala Lumpur (fourth), Jakarta (eighth), and Bangkok (ninth).  

The Middle East, Europe, and even the United States are also represented in the top rankings, with Dubai-Riyadh at number six, and the New York JFK-London Heathrow route rounding out the top 10. When it comes to domestic routes, Asia dominates the top three globally: Jeju International-Seoul Gimpo, Sapporo New Chitose-Tokyo Haneda, and Fukuoka-Tokyo Haneda. Jeju-Seoul maintains its title as the world's busiest domestic route, with 14.2 million seats available – nearly 39,000 per day.    

Analyzing routes by region, Cairo emerges as Africa's central hub, with flights departing from the Egyptian capital claiming the top five spots for routes leaving the continent. London Heathrow Airport dominates European routes, with the JFK-LHR connection taking the top spot, followed by links with Dubai and Dublin at numbers two and four, respectively. Latin America's top route is between San Juan and Orlando, followed by Lima-Santiago, while Jeddah-Cairo and Dubai-Riyadh lead the Middle East routes. The Jeddah to Riyadh route is the fastest-growing in the top 10, with a 10% increase in capacity year over year, reaching 8.7 million.    

The rankings are compiled by calculating the volume of airline seats available in both directions for each route. The rapidly expanding numbers – as well as the year-on-year increase from 4.9 million to 6.78 million for the top-ranked route, and a 1.3 million increase for Cairo-Jeddah – indicate significant growth in the Asia Pacific region, according to OAG's press release. However, these burgeoning figures are not without their environmental implications.

In 2022, aviation was responsible for 2.1% of global man-made carbon emissions, according to the Air Transport Action Group, and 3.5% of total planet-warming emissions. At the time, Matteo Mirolo from Transport & Environment, an organization advocating for cleaner transportation, warned of the consequences of the industry's expansion. "If we don't take action now, in a few years, aviation will become one of the most significant contributing factors," he stated. "We should not focus solely on the present; we must consider the forecast."  

Global Flight Route Rankings:  

• Hong Kong - Taipei        
• Cairo - Jeddah        
• Seoul Incheon - Tokyo Narita        
• Kuala Lumpur - Singapore Changi      
• Seoul Incheon - Osaka Kansai      
• Dubai - Riyadh      
• Bangkok - Hong Kong        
• Jakarta - Singapore Changi      
• Bangkok - Singapore Changi      
• New York JFK - London Heathrow    

Domestic Flight Route Rankings:        

• Jeju International - Seoul Gimpo      
• Sapporo New Chitose - Tokyo Haneda    
• Fukuoka - Tokyo Haneda  

The surge in air travel not only reflects the recovery of the aviation industry post-pandemic but also raises concerns about its environmental impact. As the world's busiest flight routes continue to expand, there is an urgent need for sustainable solutions to mitigate the carbon footprint of this growing mode of transportation.