The Urban Structure and Personal Travel: An Analysis of Portland, or Data and Some National and International Data

Urban form in the US (and now elsewhere) has tended to be “market driven” with little or no policy input and very little forethought. The advent of new, faster transportation has changed the relative accessibility of vacant land, and both the value to the owner and developers. With improvements in accessibility, more newly developable land becomes available, increasing its value to the owner and decreasing the cost of vacant developable land. Making it more possible to live at lower density at an affordable cost. This has occurred with the advent of commuter rail (in a limited band along the corridors), and to a much larger degree, with the advent of the car, ubiquitous highways, and later, highspeed freeways. Lewis Mumford2,3 has most aptly and intuitively described this response of urban form to the change in transport supply.