The Compact City or city of short distances is an urban planning and urban design concept, which promotes relatively high residential density with mixed land uses. It is based on an efficient public transport system and has an urban layout which – according to its advocates – encourages walking and cycling, low energy consumption and reduced pollution. A large resident population provides opportunities for social interaction as well as a feeling of safety in numbers and 'eyes on the street'[1]. It is also arguably a more sustainable urban settlement type than urban sprawl because it is less dependent on the car, requiring less (and cheaper per capita) infrastructure provision (Williams 2000, cited in Dempsey 2010)[2].
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The term Compact City was first coined in 1973 by George Dantzig and Thomas L. Saaty,[3] two mathematicians whose utopian vision was largely driven by a desire to see more efficient use of resources. The concept, as it has influenced urban planning, is often attributed to Jane Jacobs and her book The Death and Life of Great American Cities (1961),[1] a critique of modernist planning policies claimed by Jacobs to be destroying many existing inner-city communities.
Among other criticisms of the conventional planning and transport planning of the time, Jacobs' work attacked the tendency, inherited from the Garden City Movement, towards reducing the density of dwellings in urban areas. Four conditions were necessary to enable the diversity essential for urban renewal: mixed uses, small walkable blocks, mingling of building ages and types, and "a sufficiently dense concentration of people". The 'sufficient' density would vary according to local circumstances but, in general, a hundred dwellings per acre (247 per hectare – high by American standards, but quite common in European and Asian cities) could be considered a minimum.
Although the term was coined by American writers, it has been used more in recent years by European and particularly British planners and academics (see for example Jenks et al 1996[4]). In North America the term smart growth has become more common. The two concepts are very similar, although 'smart growth' carries more strongly normative connotations. In Australia, Steffen Lehmann has extensively written about the Compact City and Green Urbanism. His book The Principles of Green Urbanism (Earthscan, 2010; ISBN 978-1-84407-817-2) presents a series of international case studies in great detail and outlines 15 core principles for the design of compact, sustainable cities. These principles are also outlined in an article in the journal S.A.P.I.EN.S.[5]
The Compact City had a particularly strong influence on planning policy in the UK during the Labour Governments of 1997–2010. The first Labour Government in 1998 set up the Urban Taskforce under Lord Richard Rogers, which produced the report Towards an Urban Renaissance. Influenced by this report, the UK Government issued PPG 3 Planning Policy Guidance on Housing which introduced a 60% brownfield target, a minimum net residential density guideline of 30 dwellings per hectare, a sequential hierarchy beginning with urban brownfield land, maximum parking guidelines replacing the previous minima, and a policy of intensification around public transport nodes. Over the succeeding years, these targets were substantially exceeded, with the brownfield proportion reaching 80% by 2009, and average densities 43 dwellings per hectare.[6]
Whether the Compact City (or 'smart growth') does or can reduce problems of automobile dependency associated with urban sprawl has been fiercely contested over several decades. An influential study in 1989 by Peter Newman and Jeff Kenworthy compared 32 cities across North America, Australia, Europe and Asia.[7] The study's methodology has been criticised[8] but the main finding that denser cities, particularly in Asia, have lower car use than sprawling cities, particularly in North America, has been largely accepted – although the relationship is clearer at the extremes across continents than it is within countries where conditions are more similar.
Within cities, studies from across many countries (mainly in the developed world) have shown that denser urban areas with greater mixture of land use and better public transport tend to have lower car use than less dense suburban and exurban residential areas. This usually holds true even after controlling for socio-economic factors such as differences in household composition and income.[9] This does not necessarily imply that suburban sprawl causes high car use, however. One confounding factor, which has been the subject of many studies, is residential self-selection:[10] people who prefer to drive tend to move towards low density suburbs, whereas people who prefer to walk, cycle or use transit tend to move towards higher density urban areas, better served by public transport. Some studies have found that, when self-selection is controlled for, the built environment has no significant effect on travel behaviour.[11] More recent studies using more sophisticated methodologies have generally refuted these findings: density, land use and public transport accessibility can influence travel behaviour, although social and economic factors, particularly household income, usually exert a stronger influence.[12]
Reviewing the evidence on urban intensification, smart growth and their effects on travel behaviour, Melia et al (2011)[13] found support for the arguments of both supporters and opponents of the compact city. Planning policies which increase population densities in urban areas do tend to reduce car use, but the effect is a weak one, so doubling the population density of a particular area will not halve the frequency or distance of car use.
For example, Portland, Oregon, a U.S. city which has pursued smart growth policies, substantially increased its population density between 1990 and 2000 when other US cities of a similar size were reducing in density. As predicted by the paradox, traffic volumes and congestion both increased more rapidly than in the other cities, despite a substantial increase in transit use.
These findings led them to propose the paradox of intensification, which states:
| “ | Ceteris paribus, urban intensification which increases population density will reduce per capita car use, with benefits to the global environment, but will also increase concentrations of motor traffic, worsening the local environment in those locations where it occurs. | ” |
At the city-wide level it may be possible, through a range of positive measures, to counteract the increases in traffic and congestion which would otherwise result from increasing population densities: Freiburg im Breisgau in Germany is one example of a city which has been more successful in this respect.
This study also reviewed evidence on the local effects of building at higher densities. At the level of the neighbourhood or individual development, positive measures (e.g. improvements to public transport) will usually be insufficient to counteract the traffic effect of increasing population density. This leaves policy-makers with four choices: intensify and accept the local consequences, sprawl and accept the wider consequences, a compromise with some element of both, or intensify accompanied by more radical measures such as parking restrictions, closing roads to traffic and carfree zones.
Based on previous work of the Committee on Transport and Tourism[14], the European Parliament in its Resolution of 9 July 2008[15] called among other things for “drawing up customised sustainable mobility plans and supporting measures for regional and urban planning ('city of short distances'), a process in which all parties concerned should be involved from an early stage”. They referred among others to the EU strategy to combat climate change and other environmental problems.