CONCRETE evidence is emerging that China's deep commitment to infrastructure building in the last decade is paying off in answering the call to have the wealth of the coastal regions move inland to less affluent interior.

This evidence comes with the news that the Port of Shanghai's river-sea intermodal container transshipments have increased 12 per cent year on year to 7.6 million TEU in the first half, faster than the port's total container volume that posted 2.9 per cent growth rate.

This means factories are being established deep in the interior and the goods they produce are being moved to the Shanghai for export at prices which win them slots on ships going for retail shelves the world over - or else these cheerful numbers would not be forthcoming as they are.

Shanghai handled 16.32 million TEU in the first half of 2013 and the river trade proportion climbed 3.8 per cent year on year to 46.6 per cent of the total container volume, keeping Shanghai ahead of its target of having the river trade share reach 45 per cent of the whole by 2015.

We have heard much of railway development in recent years, and while progress in the rail sector undoubtedly surpasses anything in the world, there have been less note made of the great strides in less eye-catching waterway development.

In length and breath, Yangtze River is like the Mississippi with two shallow broad, muddy streams that flow across continents, one from the highlands in the north of the United States from waters flowing from the Rocky Mountains to the west and from the Canadian Shield to the north. The Yangtze and its tributaries are fed by waters running off the high plateau of Chongqing and westward, and from the mountains north and south of the river to feed its every tributary as it meanders eastward to Shanghai.

What has limited the resulting river trade in both cases was partly a lack of business and trade flow partly because bigger ships could not navigate the rivers and were of insufficient size to achieve the economies of scale demanded to keep prices from factory door to western retail shelf low enough to make the trade.

The increase in trade upstream, brought by intense dredging and river port upgrades to achieve cost-savings at intermodal transfer points far from the coast, indicates that things are working as planned. Shanghai also attributes the rapid rise in river trade transshipments to its development of the new Yangshan international shipping hub and its effort to attract mega ships, which keep unit prices low.

In the first half of the year, Shanghai's international container transshipments soared 32.7 per cent to 1.18 million TEU.