When a new terminal opens in 2017 at Singapore's Changi Airport, the world's best for five years straight according to a survey, passengers will be able to, in theory, go through check-in to boarding without speaking to another person.

Automation is important for the city-state as it faces a labour crunch across many of its industries. It is also key for Changi given it is the world's sixth busiest for international traffic and is already operating close to total capacity, having last added a terminal almost a decade ago.

Changi will be using facial recognition technology to offer self-service options at check-in, bag drop, immigration and boarding at the new terminal T4 - which according to Corrine Png, CEO of transport research firm Crucial Perspective Pte, "will be the first in Asia to do so".

Changi expects the automated process at the new terminal - which has been constructed for S$985 million ($723.57 million) - to yield manpower savings of about 20 percent in the longer term. T4 will increase the airport's overall annual capacity by 16 million passengers to 82 million.

Nine airlines will operate at T4, including the Air Asia Group, Cathay Pacific, Cebu Pacific, Korean Air, Spring Airlines and Vietnam Airlines, Changi said.

With a gross floor area of 225,000 square metres, equivalent to about 30 soccer pitches, T4 is half the size of Changi's third terminal, but it will still be able to handle two-thirds the number of its passengers.

"One of the objectives for T4 was to use it as a test bed for new concepts, new technology and new equipment," said Poh Li San, Changi Airport Group's vice president, T4 Programme Management Office.

The city-state will have a fifth terminal up and running in about a decade that will be capable of handling 50 million passengers annually in its initial phase.

In 2016, passenger traffic in Changi hit a record high of 58.7 million. Routes to Southeast Asia, north east Asia and Oceania contributed 90 percent of the growth.

Crucial's Png expects Southeast Asia's air passenger traffic to grow 6 percent annually over the next five years, making Singapore's planned new terminals all the more timely.

Changi was named the world's best airport for a fifth consecutive time at this year's World Airport Awards, which is based on a survey of air travellers and is independent of any airport control.