The budget for the expansion is 18.9 billion yuan ($3 billion), of which 800 million yuan will come from the aviation development fund.

This is likely to be the last major expansion of Baiyun. Zhang Kejian, the chairman of the facility’s listed operating company, said last year that international experience suggests airports tend to become more efficient as they grow, but not past a capacity of 80 million passengers a year, or at most 100 million. Beyond that, it is better to build another airport, he said. Similarly, Beijing has decided to build another airport, rather than further expand Capital Airport, whose designed capacity is 85 million passengers a year.

Beijing and Shanghai are the other two cities designated as main gateways for China.