Chapter 7: The Metropolitan Field: An Emerging form that may Condition the Sustainability of Transport

Urban transport systems are of increasing concern because of the continuing and rapid growth in their impacts on ecosystems and human communities. Through their emissions of greenhouse gases and criteria pollutants, their impacts are felt at all geographical scales. Yet much of the ensuing debate about the sustainability of urban transport has focussed on the density and mixity of functions of built-up areas at a relatively local scale. Arguably, this debate should be extended to whole urban regions — but within what boundaries? The day-to-day movement of people and goods over large areas was fundamental to the earliest discussions of what came to be called an “urban field”. Among the first to describe the context was Smailes, who wrote: