Determining Optimal Urban Expansion, Population and Vehicle Density, and Housing Types for Rapidly Growing Cities

This study examines the economic, social and environmental impacts of various urban development factors including urban expansion, population and vehicle density, housing type, roadway design and management, and recreation facility availability. The results are used to create guidelines for urban development that optimizes for various planning objectives including openspace (farmland and habitat) preservation, efficient public infrastructure and services, public health and safety, efficient transportation, affordability, economic productivity and opportunity, and urban livability (local environmental quality). This analysis indicates that in geographically unconstrained cities, optimal densities can range from 20-40 residents per hectare, optimal vehicle ownership can range from 300-400 vehicles per 1,000 residents, and a majority of housing can be single-family, but as urban expansion is constrained, optimal densities increase, optimal vehicle ownership rates decline, and a greater share of housing should be multi-family. To be efficient and equitable, cities should provide diverse housing and transport options which respond to consumer demands, particularly affordable housing in accessible, multimodal neighborhoods, and affordable travel modes, with pricing or roadway management that favor resource-efficient modes, plus convenient access to parks and recreational facilities. Various Smart Growth and Transportation Demand Management (TDM) policies can help achieve thes