All the options ADP Ingénierie (ADPI) has submitted to the Ministry of Transport will quadruple the airport’s current capacity of 25 million passengers by 2030 as approved by the government.

They include removing the existing domestic terminal T1 and building two new ones in the south to make it a total of three terminals.

But the main differences between the various options lie in the number and type of runways.

One is to build three independent parallel runways, which will allow three aircraft to take off or land at the same time.

Another option is to have one independent runway and two parallel dependent runways, which will allow only one aircraft to take off or land.

Yet another proposal is to build two pairs of parallel dependent runways like at the Long Thanh International Airport being built near Ho Chi Minh City. The Hanoi airport currently has two dependent runways which have developed cracks and factures due to overuse.

One of the challenges in upgrading the airport is acquiring land since Noi Bai is located in a highly populated area where historical temples add to the difficulty.

Deputy Prime Minister Trinh Dinh Dung on Monday instructed the transport ministry to review all the options and focus on those requiring the least land acquisition.

The airport served 26 million passengers last year and its operator expects the number to rise to 29 million this year and 63 million by 2030.

Rising air travel demand means Vietnam needs to quickly upgrade existing airports and build new ones. Last year its 21 public airports served 103.5 million passengers, up 11 percent, and the figure is set to rise to 112 million this year, according to the Airports Corporation of Vietnam.