ABSTRACT
The monocentric model presented in the last chapter explains spatial patterns of urban rents and densities, along with the segregation of land among different classes of firms and households, in terms of a single variable: distance from the central business district (CBD). Real cities have always had other important reference points, such as port or rail terminals, churches, stadiums, parks and many more. To the extent that these things were located away from the CBD, they constituted secondary centers that might have significant impacts on spatial patterns in the city. Still, for most cities, the CBD was so clearly dominant in its influence on economic and social interaction that it was the only logical place to start in any explanation of the overall shape of the city.
