For the past 10 years, Mr Davis Cheung has been travelling from Hong Kong to Singapore for business up to four times a year.

And once every two years, Mr Cheung, 45, a finance director of a multinational firm, takes his family to Singapore for a holiday.

He is one of 2.8 million passengers who travelled between Hong Kong and Singapore from January to October this year.

Hong Kong-Singapore has been ranked one of the top five passenger routes by Hong Kong International Airport (HKIA).

According to Airport Authority Hong Kong, 3.8 million passengers travelled between the two cities last year, which saw an average of 321 flights serving the route every week.

A spokesman for Airport Authority Hong Kong said: "HKIA is connected to half of the world's population in less than five flying hours. Currently, there are 100 airlines operating 190 destinations around the world at HKIA.

"Last year, HKIA welcomed 68.5 million passengers and handled 406,020 flight movements, representing annual growth of 8.1 per cent and 3.8 per cent, respectively."

To cope with the growing air traffic demand, HKIA is building a three-runway system, said the spokesman.

The construction of the third runway, which began in August this year, involves reclaiming 650ha of land and building a new passenger concourse, a new 3.8km-long runway, a new automated people-mover system and a new baggage handling system.

"It is an undertaking almost equivalent in scope to building a whole new airport," said the spokesman.

The project is expected to be completed by 2024.

International air traffic expert IATA Consulting estimates that it will help HKIA to handle up to 102 million passengers, 8.9 million tonnes of cargo and 607,000 aircraft movements a year by 2030.