Ch. 13.2 Models of Urban Structure
Three models demonstrate cities grow in wings wedges nodes
A city grows outward in five consecutive rings. The innermost zone is CBD. This is were nonresidential activities are located. Then the second ring contains poorer quality housing. Next is the third ring which is working class. The fourth ring is middle class housing. The final zones are "bedroom communities".
The multiple nuclei theory states that some activities are attracted to certain nodes and others try to avoid them. For example, a university node might attract well educated residents, pizzerias, and book stores.