They dwarf 7.5 million-strong London and even laugh in the face of the likes of Los Angeles. They are the Mega-Urban Regions, and they are spreading across Asia now.
MURs for short, the term covers the massive urban aggregations formed when major cities expand so much their sprawl swallows up much of the land separating them from neighboring population centers.
Thus, in one of the longest-established MURs, Tokyo is all-but linked with the cities of Osaka, Kyoto, Kobe and Nagoya. Meanwhile southern China has seen the explosive growth of Shenzhen and Guangzhou, forming an urban jungle nestling against the already packed territory of Hong Kong.
Even the sober statisticians of United Nations housing and cities agency UN Habitat label the expansion of Asia's cities "astounding," noting that many are doubling their population every 15 to 20 years
By the end of the next decade, the agency predicts, two thirds of the people in South East Asia will live in one of five MURs, based around Bangkok, Kuala Lumpur, Singapore, Manila and the cities of Java, Indonesia's most populous island.
But even these will be small compared to the 60 million who will be living in the Tokyo MUR by then, the 80 million or so centered around Shanghai and the astonishing 120 million who will be in Hong Kong, Shenzhen and Guangdong.
South Asia, meanwhile, is growing MURs of its own, as a similar pattern of mass internal migration from the countryside draws millions to Delhi, Mumbai, Dhaka and the likes.
There are a number of problems associated with MURs, experts argue, not least their often bland, homogenous character.
"As cities expand, if they expand like an oil slick, Los Angeles-style, it's a nightmare," says Ricky Burdett, professor of architecture and urbanism at Cities Program in the London School of Economics.
In some cases, such as Shenzhen in southern China, which grew from a fishing village to a metropolis of 9-10 million people in little more than two decades, it was a case of "building a city from scratch," notes Professor Aprodicio Laquian from the University of British Columbia, an expert on MURs.
"It doesn't have a history and doesn't have a soul," he says.
More practically, there are severe problems extending services such as public transport, water and sanitation through fast-expanding urban areas covering hundreds of kilometers. A key element is having a unified MUR-wide authority to impose some order on the growth.
"The Chinese are trying to do it, and more than any other country they can do it, as they can just issue a directive from Beijing," Laquian says.
"But if you really want to do it democratically, it is really very difficult. But that's the biggest challenge - without a government structure you will have a lot of fragmented, uncoordinated, duplicating functions."
Many of the worst managed MURs are in South Asia, he says, singling out the Bangladeshi capital of Dhaka - with a current population of 12.5 million, predicted to hit 21 million within a decade - and its "lots of fragmented local government."
"The transport system is a mess, the services are not being delivered," he notes.
What do you think? Do you live in an MUR?
My girlfriend is from Odawara, a suburb city of Yokohama. I went with her to Japan recently and had the time to experience part of the MUR of Tokyo. Simply put, Tokyo has it 80 percent right! Subways, buses and trains (both commuter and bullet) serve the swell of humanity pretty well, though there are problems. Infrastructure strain continues to be a problem, as literally millions take the mass transport system. Sanitation is also a problem (again, because of so many people), and the dense living areas means there is no room for greenspace.
There are some highways in Tokyo, but they are constantly crowded and people try to avoid them like the plague. Yet more people walk and take bikes, so I think this is one example, which with a few tweaks and better planning, can serve other MURs and cities for the future.
The Principal Voices forum has missed one major key point of urban failure: real estate land sharking and money laundering in housing sales, including fake earthquake-proof housing.
These are main elements blocking the success of the Japanese Mega Cities urban renewal plan, in particular, slow improvement of conventional commuter rail and subway networking in favor of bland elevated express highway systems during past three decades. Today, these roadway systems are altogether obsolete.
The ever-spreading MURs in Asia are not only an urban nightmare, but are also a fight for survival for rural emigrants. The lack of well-developed education systems, electricity, water supplies and medical facilities, and non-existent career opportunities, are major reasons for rural migration, resulting in a near-collapse of urban society.
Itís a case of minimum resources vs. population explosion. The only way to resolve the problem is to provide rural areas with their fair share of health, educational and economic development.
Mega Manila is actually the biggest metropolitan area in South East Asia today. It does not just comprise the cities around Manila, it now includes numerous urban areas in nearby provinces as well. With the extent of its urbanization, the combined population of mega-Manila today can be pegged at over twenty million. Other big Philippine cities are almost integrating with the towns around them, too, including Cebu, Davao and Baguio in the north.
The ever-spreading MURs in Asia is not only an urban nightmare, but is also a fight for survival for rural emigrants. The lack of well developed education systems, electricity, water supplies and medical facilities, and non-existent career opportunities, are major reasons for rural migration, resulting in a near-collapse of urban society.
Minimum resources verses population explosion -- the only way to resolve the problem is to provide rural areas with their fair share of health, educational and economic development.
One issue to tackle about MUR's is that of land ownership. It isn't always possible to resolve all the cases of land ownership, making it harder to expand the roads and other important infrastructure.
The situation of MURs in South Asia is of serious concern. One of the problems in the region is politicized rural/ urban planning. The issue has not addressed democratically as yet. Rural migration can be dealt with by satisfying people socially and economically.
Civilization is jumping headlong towards MURs all over the world, thanks to an era of liberalization.
The city is changing fast, and is getting close to other European capitals. What it really needs is space for circulation and space for reunions, for coming to a common space or sense.
India's commercial capital, Mumbai, with its ideal geographical location, has all the potential to take up the challenge of fast growing urbanization.
But unfortunately, the city with 14-15 million people is on the verge of collapse because of a lack of political will to strengthen its century-old infrastructure and to relocate the slums from the heart of the city, the two biggest stumbling blocks for its development into one of the super cities of the world.
Living in one fast growing city In India is not getting better any more! The city has seen unprecedented development, it is growing in leaps and bounds and with it are the problems too.
The urbanization has taken everybody by surprise. The city adds 3,000 vehicles every week, a staggering number.
There are huge problems because of urbanization, for example city poverty is a big problem. The city has crumbling public transport which is not able to meet the needs of the common people, so many people turn to private transport which puts a strain on the Infrastructure. Crime has gone up as the difference between the rich and poor is widening.
Sustainable development is the only solution to any new growing city, where the government needs to think of the needs of the common man.
Living in this nation's Mega Capital Tokyo suburb, the Principal Voices forum has missed one major key point of urban failure: real estate land sharking and money laundering housing sales, incidents including fake earthquake-proof housing.
These are main elements blocking success in the Japanese Mega Cities urban renewal plan, in particuluar, slow improvement of conventional commuter rail and subway networking in favor of bland elevated express highway systems during past three decades. Today, these roadway systems are altogether obsolete.
I don't live in an MUR and don't think I would like to. The best solution to problems in developing nations like India is for the government to improve infrastructure and create better paying jobs in rural areas, so less people would be forced to migrate to MURs for a better life.
Let's face it; most people from rural areas are not thrilled by the idea of moving to Bombay/New Delhi only to find themselves living in slums. They are desperate and have no choice.
I wanted to make a comment to Achandra.
Of course, the best solution to problems in developing nations like India is for the government to improve infrastructure and create better-paying jobs in rural areas, so fewer people would be forced to migrate to MURs for a better life.
But in my point of view we have to stay realistic. I will talk from my experience and my knowledge from what I know here in Cairo.
You raised a solution for the government, but I think we have to say how the government should provide better infrastructure. So my idea is that the people have to pay taxes to ensure the government has money to build better infrastructure and create better-paying jobs.
Because at the moment, 5% of the Egyptian population pays taxes and we are a population over 70 million!! So I think when everyone begins to pay taxes we will be able to ensure that all people in Cairo will have a much better life.
As an example we have to see Germany -- they have some of the highest taxes in the world and at the same time very good social coverage.
If every emerging city bases its transport system on the model of Hong Kong, they will be in wonderful shape.
But even though Hong Kong's urban transport planners have done an amazing job, (most notably privatizing its subway system and providing legal means to ensure its profitability), Chinese law limits Hong Kong planners' ability to coordinate with cities on the mainland, such as Shenzhen and Guangzhou.
Shanghai seems to be learning much from Hong Kong's planners, but its transport infrastructure remain decades behind that of Hong Kong and its enormous area and huge population will make the development of an efficient transport system that much more difficult.