The Government is absolutely right to build Changi Airport's Terminal 5 in phases according to scalable building design modules (Building ahead key to Changi's success: Khaw; Aug 4).

What had worked for its bold vision in constructing the then new Changi Airport way ahead of demand in the 1970s against the advice of international aviation and financial experts may well end up in tears for T5.

Four reasons come to mind.

First, the airport infrastructure of many countries in the region have either caught up with or are fast catching up with Singapore.

Competition is much stiffer today.

For example, 30 years ago, the Gulf countries were nowhere in sight as air hubs.

Today, the Dubai International Airport is ranked the busiest in the world in terms of international passenger traffic.

Who knows, that mantle could be assumed by one of our close neighbours tomorrow.

Second, the skies over Malaysia, Singapore and Indonesia are already among the busiest in the world.

The rapid growth in intra-Asian air travel will put a further strain on aviation capacity.

How many flights can airports in the region accommodate without posing a danger to passenger safety and other service standards?

The sky may be the limit for Changi's ambitions, but the air space above and around Singapore is not limitless.

Third, advancements in aviation technology allowing planes to travel faster and for longer distances without refuelling could alter the route architecture and undermine the hub-and-spoke strategy that has served Changi and Singapore well over the years.

Fourth, advancements in high-speed rail technology and its eventual roll-out across the Asian continent could also crimp the growth of the airline industry.

Such alternative and sustainable modes of travel must be welcomed to relieve the potential choke points in the air.

Changi has done fairly well in developing an airport as a destination - not merely as a point of embarkation and disembarkation - ahead of the competition.

But it cannot afford to live on past glories or the operating formulas of yesteryear, and must continue to raise its service offerings to a higher plane.

Singapore can be the leading global city for seamless multi-modal transport and logistics connectivity and delivery.

And it must organise itself to seize this nascent opportunity as soon as possible.

Toh Cheng Seong