The document summarizes Homer Hoyt's sector theory model of urban land development. The model proposes that cities grow outwards in sectors defined by transportation routes rather than concentric circles. It identifies central business districts, industrial zones, and high, middle, and low-income residential neighborhoods arranged in sectors radiating from the city center along transportation corridors. The model accounted for the influence of transportation costs on land use patterns. While influential, it is limited by only considering rail lines and not more modern factors influencing urban growth.