An interview with Pedro B Ortiz, a former Deputy Mayor of Madrid and Director General for Metropolitan Planning at Madrid's Regional Government about his experiences and theories of the Metro-Matrix Method which he explains in a new book: The Art of Shaping the Metropolis.

Pedro is currently a Senior Urban Consultant at the World Bank in Washington DC along with other Multilaterals and Governments or Consultancy firms and has for many years been a board member of the International Urban Development Association.

In the interview he discusses his Metro-Matrix Method and the metaphor of chess and tripods it utilises to help understand how mega-cities need to expand both in the developed and developing world.

A radical part of his proposal is the emphasis placed on reaching a potential consensus with citizens in the future. While this is an ideal to which is paid lip service by some administrations in quoting the Brundtland Commission that development to be sustainable "should not compromise the needs of future generations", this system of decision making actually tries to make it real in a democratic fashion.

He also discusses whether cities should stop growing, and what is the optimal size for a city and for its inhabitants each to occupy. He draws on the examples of Istanbul and Los Angeles. He also discusses cities in developing countries particularly South America.

He describes the conditions under which suburbia, urban freeways and six lane interchanges might disappear in the future. This  requires the development of mass transit bus and rail networks to satisfy local and long distance needs.