The primary concern is the public welfare,[1][2] which includes considerations of efficiency, sanitation, protection and use of the environment,[1] as well as effects on social and economic activities. In developing any plan for a community (whether commercial, residential, agricultural, natural or recreational), urban planners must consider a wide array of issues including sustainability, existing and potential pollution, transport including potential congestion, crime, land values, economic development, social equity, zoning codes, and other legislation.