While China's idea of a tunnel across the Taiwan Strait remains a dream, a bridge across the Pearl River Delta to connect Hong Kong with Guangzhou through Macau and Zhuhai will soon emerge into reality. Work is well on schedule and hopefully by the end of 2016, travellers from one side of the delta will be able to drive over to the other in just about 45 minutes, instead of four hours that it now takes to go by roads skirting the top of the delta. There are, of course, steamers and ferries, but it's not the same thing as direct driving, with time and circumstances under one's control.

First bred in the mind of Hong Kong tycoon Gordon Wu, which many had once thought was a crazy idea, the governments of Hong Kong, Macau, and China have now joined in earnest and are sharing the $9 billion cost of the 42-km sea link. It will actually consist of a six-lane network of bridges and a 6.7-km stretch of undersea tunnel. Two artificial islands will support the cross-over, one off Gongbei in Zhuhai and the other west of the boundary of the Hong Kong Special Administrative Region (SAR).

In fact, China is so interested in bridging the delta that it's contemplating another link to bring Shenzhen, a bustling special economic zone across the border from Hong Kong, and Zhuhai, also marked as a special economic zone but hasn't yet quite started to bloom, closer together. Zhuhai is still an affordable and relatively under-populated (1.8 million) location, and businesses from Shenzhen, many of which are from Hong Kong, are looking across the delta as they struggle with high land and labour costs. They just need a quick cross-over.

At 51 km, the new link will be longer than the Hong Kong-Macau-Zhuhai connection and will take off from some 20 miles north of the Hong Kong border to reach the city of Zhongshan, just next to Zhuhai. It's going to cost around $5 billion and is scheduled for completion by 2021.

All this is part of China's grand design to turn the Pearl River Delta into the world's largest mega-city, and a grander one to make it a one-hour living zone. It means all the nine delta cities - Shenzhen, Dongguan and Huizhou in the east; Zhuhai, Zhongshan and Jiangmen in the west; and Guangzhou, Foshan and Zhaoqing in the centre - will be within an hour's distance of one another. So will be Hong Kong, which retains a separate identity but plays an important economic role in the development of the delta. With a population of more than 60 million, the delta region accounts for nearly 30 per cent of China's exports. Connectivity within the region is, therefore, absolutely essential and more than 150 major projects to improve its infrastructure, especially in the areas of transport, water, energy supply, and telecommunications are underway.

A blueprint made public in 2008 contemplates a colossal transport network of more than 4,000 km of roads, tunnels, bridges, and intra- and inter-city rapid transits to tie up the entire area, so that residents may live in one city and go to work in another within an hour or even less. Hong Kong travellers can similarly "beep" around the delta, in fact to 16 cities around it, using their Hong Kong-specific Octopus smart cards. Besides, Hong Kong on its part is building a 140-km express rail link, with its terminus in West Kowloon, to further enhance connectivity with its north and west, When it becomes fully operational in 2015, travel time between Hong Kong and Guangzhou will be reduced to a mere 45 minutes.

Connectivity is becoming so crucial an issue for Hong Kong business circles that its government is even toying with a proposal to open up part of its northern border buffer zone and turn it into a commercial district with an eye on the delta. Some Hongkongites don't like the idea for political reasons but the government thinks it's not such a bad one since Hong Kong is already closely knit with South China anyway and there's no way the SAR can prosper on its own any more.

The integrated Pearl River mega-city will create a 16,000 sq mile urban area that's nearly 26 times larger than Greater London. Without an efficient urban connectivity, such an entity simply can't work. What China is seeking to do is set a standard of urban mobility for current and future mega-cities that are coming to existence, by the sheer force of urbanisation, in Beijing, Shanghai, and other places in China and around Asia. Asian town planners have yet to wake up to the problem yet. Even the US, where Greater Los Angeles roughly parallels the Pearl River mega-city in geographical terms, hasn't quite got its connectivity question fully sorted out.