In 1925, Burgess proposed a descriptive urban land use model that divided cities into concentric circles expanding from downtown to the suburbs. This representation was built from Burgess’s observations of several American cities, notably Chicago, for which he provided empirical evidence. The model assumes a relationship between the socio-economic status (mainly income) of households and the distance from the Central Business District (CBD). The further from the CBD, the better the quality of housing, but the longer the commuting time. Thus, accessing better housing is done at the expense of longer commuting times (and costs). According to this monocentric model, a large city is divided into six concentric zones:
- Zone I: Central Business District (called the “loop” in Chicago), where most of the tertiary employment is located and where the urban transport infrastructure converges, making this zone the most accessible.
- Zone II: Immediately adjacent to the CBD, a zone where many industrial activities locate to take advantage of nearby labor and markets. Further, most transport terminals, namely port sites, and railyards, are located adjacent to the central area.
- Zone III: This zone is gradually being reconverted to other uses by expanding manufacturing / industrial activities. It contains the poorest segment of the urban population, notably first-generation immigrants living in low-cost housing.
- Zone IV: Residential zone dominated by the working class and those who could move away from the previous zone (often second-generation immigrants). This zone has the advantage of being located near the major zones of employment (I and II) and thus represents a low-cost location for the working class.
- Zone V: Represents higher quality housing linked with longer commuting costs.
- Zone VI: Mainly high-class and expensive housing in rural, suburbanized settings, with the highest commuting costs. Before the mass diffusion of the automobile (in the 1930s), most of these settlements were located next to rail stations.
According to Burgess, urban growth is a process of expansion and reconversion of land uses, with a tendency for each inner zone to expand towards the outer zone. In the above figure, zone II (Factory zone) is expanding towards zone IV (Working class zone), creating a transition zone with the reconversion of land use. Although the Burgess model is simple and elegant, it has drawn criticisms:
- The model is too simple and limited in a historical and cultural urban context that prevailed until the 1950s. It is a product of its time.
- The model was developed when American cities were growing very fast in demographic terms, and when motorized transportation was still uncommon, most people used public transit. The expansion thus involved the reconversion of existing land uses. This concept cannot be applied effectively in a contemporary (from the second half to the 20th century) context where highways have enabled urban development to escape the reconversion process and occur directly in the suburbs.
- The model was developed for American cities and had limited applicability elsewhere. It has been demonstrated that pre-industrial cities, notably in Europe, did not follow the concentric circles model. For instance, in most pre-industrial European cities, the center was much more important than the periphery, notably regarding social status. The Burgess concentric model is consequently partially inverted.
- There were many spatial differences in ethnic, social, and occupational status, while there was a low occurrence of functional differences in land use patterns. The concentric model assumed a spatial separation of workplace and place of residence, which was not generalized until later in the twentieth century.
However, the Burgess model remains useful as a concept explaining concentric urban development, as a way to introduce the complexity of urban land use, and to explain urban growth in American cities in the early-mid 20th century.