Changi Airport's new passenger terminal looks finished from the outside with "Terminal 4" embossed on a wall at the departure level, and new roads and bridges constructed, along with a 68m-high control tower.

More than two years since construction started, a multi-storey carpark just in front of T4, an outdoor holding area for taxis and a bus terminus are also nearing completion.

Works are expected to be completed by the end of the year.

T4, however, will not be ready to receive travellers and visitors just yet, spokesman for Changi Airport Group Ivan Tan told The Straits Times. The opening is slated for the second half of next year.

The next phase of works will involve the testing of airport systems and equipment as well as operational readiness trials.

Unlike the other three terminals, T4 will see a massive rollout of self- service and automated options for check-in, bag tagging, immigration clearance and aircraft boarding.

Passengers will be subject to centralised screening instead of being screened at the gatehold rooms just before boarding - the system in place at the other terminals.

To minimise teething problems, extensive tests will be conducted later this year.

There are plans for more than 50 trials, including live flights, ahead of T4's opening.

This is more than double the number of trials for T3, which opened in 2008.

Built to handle up to 16 million passengers a year, T4 as well as expansion works at T1 will increase Changi's total capacity to 85 million passengers.

Cathay Pacific and budget airline AirAsia were the first two carriers to announce plans to move to the new terminal.

AirAsia's Singapore chief executive Logan Velaitham is looking forward to moving the airline's operations to the new facility.

The extensive use of automation and technology is a key attraction, he said.

This will not only benefit customers but also help the airline cut operating costs by as much as 40 per cent, with less reliance on manpower. Mr Logan said: "We expect huge operational and productivity gains which we aim to translate into lower fares for our customers.

"At T4, AirAsia passengers can also look forward to a new travel experience which will offer seamless and easy processes from start to end."

While there will be no Skytrain linking T4 to the other terminals, those with connecting flights will be moved to a transfer lounge where they will be bussed to T2.

They can take a Skytrain to T1 and T3 from there.

Undergraduate P.S Sandhu, 19, said: "Automation is definitely a step in the right direction in terms of convenience and efficiency.

"But there must also be adequate provisions made so that travellers who may have issues with check-in or other processes can move to manual counters so they don't hold up the automated lanes."