Explain one weakness of urban models in explaining patterns of settlement

A weakness of urban models in terms of settlement patterns is the phenomenon of urban sprawl, by which, after the population saturation of urban centers, cities are expanding in a disorderly way towards the suburbs, where there is no uniform planning. and according to the needs of the population. Thus, the suburbs are characterized by the lack of certain public services in an adequate way for all their inhabitants: lack of schools, hospitals and other services in a planned way; lack of routes and highways that facilitate mobility, etc.