Planning Process: Urban Theories and Concepts

Urban planning theorists and theories

Urban planning theory is organised around a small set of named thinkers, and examiners test whether you can link each one to the idea or model he or she is credited with. Most wrong options swap a correct name with an idea from another thinker, so learn each pair as a unit.

James Q. Wilson and George L. Kelling proposed the broken windows theory, which holds that visible disorder signals neglect and encourages further crime, so small maintenance measures are a crime-prevention tool. Sherry Arnstein's ladder of citizen participation ranks forms of public involvement, from manipulation at the bottom to citizen control at the top. Henry Lefebvre's right to the city is a claim that urban inhabitants should have a say in producing and using urban space. Richard Florida's creative class thesis argues that a group of workers in knowledge and creative professions drives urban economic growth.

The Chicago School of urban sociology, led by Robert Park and Louis Wirth, developed urban ethnography as its method. Jacob Riis documented tenement housing through photography, Charles Booth mapped poverty in London, and John Snow linked cholera deaths to a water pump on a map.

Ebenezer Howard's Garden City is a self-contained town of limited population, about 32,000 persons, surrounded by an agricultural belt. Le Corbusier proposed the Radiant City, Frank Lloyd Wright the dispersed Broadacre City, and Soria y Mata the linear city. Patrick Geddes is associated with conservative surgery, the careful renewal of old city fabric, and with the valley section, a diagram of a region from hilltop to valley. Clarence Perry's neighbourhood unit places an elementary school so that children can walk to it within about a quarter mile. Daniel Burnham promoted the City Beautiful movement, and Charles Montgomery wrote on the Happy City.

C. A. Doxiadis founded Ekistics, the science of human settlements, whose five elements are Nature, Man, Society, Shells and Networks. Ray Oldenburg's third place theory describes informal public gathering spaces beyond home and work, Oscar Newman's defensible space links design to crime prevention, and McGee and Gemburg's desakota model describes intensive mixed rural-urban development in Southeast Asia.

Planning and zoning terminology

Planning and zoning vocabulary is tested through short definitions, so precise meanings matter more than memorised labels.

NIMBY (Not In My Back Yard) describes organised local resistance to a development or public project near one's home. Tactical urbanism consists of short-term, low-cost, scalable interventions that test change in a neighbourhood. Suburbanisation is the growth of residential areas on the outskirts of a city. Figure ground relationship is a solid-void plan that shows built mass against open space. Transit oriented development (TOD) concentrates building intensity around transit stations and corridors. Transferable development rights (TDR) allow unused development potential of one plot to be transferred to another. A town planning scheme (TPS) reconstitutes plots and redistributes land for roads and amenities. A cul-de-sac is a dead-end street.

Floor area ratio (FAR) is the total built-up floor area divided by the plot area. Ground coverage is the footprint of the building divided by the plot area. Therefore the number of floors equals FAR divided by ground coverage. For example, on a 300 m^2 plot with 50% coverage and FAR 2.5, the footprint is 150 m^2, the total permitted floor area is 750 m^2, and the number of floors is 5. When FAR is increased under incentive zoning, the additional permissible floor area equals the new FAR times the plot area minus the floor area already built.

Zoning systems differ in what they regulate. Euclidean zoning strictly segregates land uses into separate zones. Form-based zoning regulates the building envelope and public realm rather than use, and therefore shapes the character of streets. Inclusionary zoning requires provision of housing for the urban poor or economically weaker sections. Performance zoning regulates development by assessing its impacts on the surroundings.

Urban land use models

Urban land use models describe how activities arrange themselves around a city's centre, and each model is defined by its structure.

Alonso's bid rent theory explains land use through the rent each activity can pay at a given distance from the central business district (CBD). Bid rent curves slope downward with distance, and their steepness reflects how strongly an activity values accessibility. Retail, which depends on central locations, has the steepest curve and the highest rent near the CBD. Manufacturing has an intermediate gradient, and residential use, which trades accessibility for space, has the flattest curve.

The Burgess concentric zone model arranges the city in rings radiating from the CBD. Zone II, the zone in transition, lies just outside the CBD and mixes residential and commercial or light industrial uses, with deteriorating housing.

The Harris and Ullman multiple nuclei model describes a polycentric city that grows around several independent centres rather than a single CBD. Homer Hoyt's sector model extends land uses outward in wedges along transport routes. Hägerstrand's work concerns the spatial diffusion of innovations and time geography, not land use zones.

Lowry's model of metropolis (1964) links basic employment, population-serving employment and residential population through two spatial interaction sub-models. Each sub-model is singly constrained, meaning that one set of totals, either origins or destinations, is fixed while the other is not.

Survey research methods

Survey research depends on choosing the right measurement scale and the right sampling method, and questions often test which method fits a given situation.

A Likert scale presents ordered agreement categories, such as strongly agree to strongly disagree, and is the standard instrument for measuring attitudes, opinions and perceptions. A ratio scale has an absolute zero and suits quantities such as height, while the Richter scale measures earthquake magnitude and is not a survey instrument.

Sampling methods are divided into probability methods, in which every unit has a known non-zero chance of selection, and non-probability methods, in which selection depends on judgement or accessibility. Convenience sampling is a non-probability method in which respondents are drawn from people who are easy to contact or reach. Snowball sampling is also non-probability, but the sample grows through referrals from earlier participants. Simple random and stratified random sampling are probability methods.

In a stratified sample that must reproduce the population's composition, the number of respondents in each group equals the group's percentage share multiplied by the total sample size. The required number of respondents in a combined subgroup is the sum of the shares of its component groups times the sample size. For example, if two groups make up 10% and 15% of the population and the sample is 400, the subgroup receives 400 \times 0.25 = 100 respondents.

Gini coefficient income inequality

The Gini coefficient is the standard single-number measure of income inequality. It is derived from the Lorenz curve, which plots cumulative percentage of population on the horizontal axis against cumulative percentage of income on the vertical axis.

The line of perfect equality runs diagonally from the origin. The further the Lorenz curve bows away from this line, the greater the inequality. If area A is the region between the equality line and the Lorenz curve, and area B is the region under the Lorenz curve, then the total area under the equality line is A + B. The Gini coefficient is therefore G = A/(A+B), which ranges from 0 for perfect equality to 1 for perfect inequality.