Soon more than 550 cities world wide will have a population of more than one million. In 2030 eighty percent of the world's population will live in cities. Megacities have traditionally been economic and political power centers but today the fastest growing cities are in developing nations.The new challenge is that cities are growing helter skelter rather than planned. There is an acute need for new models of city planning to prevent collapses under such huge social, economic and environmental pressure. If cities are to remain livable, the problems of population increase must be understood and dealt with. Cities on Speed shows how four different megacities are dealing with this challenge. What are the visions and the solutions and how do they affect the inhabitants?CairoPreviously only 12 million people lived in Cairo and the city was neat and tidy. Today Cairo has a population estimated at 20 million with six giant Garbage Villages that have evolved into towns within the city. Nobody can keep up with the speed at which the city is growing and their garbage piles up in the streets.