Editing Smart growth (section)

==Smart growth, urban sprawl and automobile dependency==
Whether smart growth (or the "compact City") does or can reduce problems of [[automobile dependency]] associated with urban sprawl have been fiercely contested issues over several decades. A 2007 meta-study by Keith Barthomomew of the University of Utah found that reductions in driving associated with compact development scenarios averaged 8 percent ranging up to 31.7 percent with the variation being explained by degree of land use mixing and density.<ref>{{cite journal|last1=Bartholomew|first1=Keith|title=Land Use-Transportation Scenario Planning: Promise & Reality|journal=Transportation|date=2007|volume=34|issue=4|pages=397–412|doi=10.1007/s11116-006-9108-2|s2cid=15933068}}</ref> An influential study in 1989 by [[Peter Newman (environmental scientist)|Peter Newman]] and Jeff Kenworthy compared 32 cities across North America, Australia, Europe and Asia.<ref>[[:File:Petrol use urban density.svg|Cities and Automobile Dependence: An International Sourcebook, Newman P and Kenworthy J, Gower, Aldershot, 1989.]]</ref> The study has been criticised for its methodology <ref>MINDALI, O., RAVEH, A. and SALOMON, I., 2004. Urban density and energy consumption: a new look at old statistics. Transportation Research Part A: Policy and Practice, 38(2), pp. 143-162.</ref> 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 ex-urban residential areas. This usually holds true even after controlling for socio-economic factors such as differences in household composition and income.<ref>e.g. FRANK, L. and PIVOT, G., 1994. Impact of Mixed Use and Density on Three Modes of Travel. Transportation Research Record, 1446, pp. 44-52.</ref> 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:<ref>{{cite book|title=Transport Reviews Volume 29 Issue 3 (2009)}}</ref> 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.<ref>e.g. Bagley, M.N. and [[Patricia Mokhtarian|Mokhtarian, P.L.]] (2002) The impact of residential neighborhood type on travel behavior: A structural equations modeling approach. Annals of Regional Science36 (2), 279.</ref> 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.<ref>e.g.Handy, S., Cao, X. and [[Patricia Mokhtarian|Mokhtarian, P.L.]] (2005) Correlation or causality between the built environment and travel behavior? Evidence from Northern California. Transportation Research Part D: Transport and Environment10 (6), 427-444.</ref>

===Paradox of intensification===
Reviewing the evidence on urban intensification, smart growth and their effects on travel behaviour Melia ''et al.'' (2011)<ref>{{cite journal | last1 = Melia | first1 = S. | last2 = Barton | first2 = H. | last3 = Parkhurst | first3 = G. | year = 2011| title = The Paradox of Intensification | url = http://eprints.uwe.ac.uk/10555/2/melia-barton-parkhurst_The_Paradox_of_Intensification.pdf | journal = Transport Policy | volume = 18 | issue = 1| pages = 46–52 | doi = 10.1016/j.tranpol.2010.05.007 | s2cid = 54022116 }}</ref> found support for the arguments of both supporters and opponents of smart growth. 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 citywide 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 zone]]s.

In contrast, the city of Cambridge, Massachusetts reported that its Kendall Square neighborhood saw a 40% increase in commercial space attended by a traffic decrease of 14%.<ref>"Car-free commuting push pays off in Kendall Square" Boston Globe, July 25, 2012. http://www.boston.com/news/local/massachusetts/articles/2012/07/25/in_kendall_square_car_traffic_falls_even_as_the_workforce_soars/</ref>

A report by CEOs for Cities, "Driven Apart," showed that while denser cities in the United States may have more congested commutes they are also shorter on average in both time and distance. This is in contrast to cities where commuters face less congestion but drive longer distances resulting in commutes that take as long or longer.<ref>Driven Apart, CEOs for Cities, 2010 {{cite web |url=http://www.ceosforcities.org/research/driven-apart/ |title=Driven Apart &#124; CEOs for Cities |access-date=2012-11-29 |url-status=dead |archive-url=https://web.archive.org/web/20121031233937/http://www.ceosforcities.org/research/driven-apart |archive-date=2012-10-31 }}</ref>

===Proponents===
* [[Edward L. Glaeser]]<ref>{{Cite web| url=http://www.hks.harvard.edu/var/ezp_site/storage/fckeditor/file/pdfs/centers-programs/centers/taubman/skilledcities.pdf | title=Smart Growth: Education, Skilled Workers, & the Future of Cold-Weather Cities | author=Edward L. Glaeser | date=2005-04-27 | access-date=2012-07-09 | archive-date=2012-12-03 | archive-url=https://web.archive.org/web/20121203003620/http://www.hks.harvard.edu/var/ezp_site/storage/fckeditor/file/pdfs/centers-programs/centers/taubman/skilledcities.pdf | url-status=dead}}</ref><ref>{{Cite web | url=http://www.planetizen.com/node/56661 | title=An Argument for Housing Choice}}</ref><ref>{{Cite web | url=http://crankyhermit.blogspot.ca/2012/03/will-zappos-tarnish-their-culture-with.html | title=Blogger}}</ref>
* [[Rollin Stanley]]