||This article needs attention from an expert in Transport. (December 2012)|
Peak car (also peak car use or peak travel) is a hypothesis that motor vehicle distance traveled per capita (expressed as vehicle kilometers or miles traveled per person), predominantly by private car, has peaked in at least eight major developed countries. There are two variants of the hypothesis, one (sometimes called 'saturation' or 'plateau') that having reached a peak, car use per head will continue at about the same level indefinitely into the future, the other that after peaking car use may in future show a prolonged declining trend. Places where it is suggested that car use has peaked include Australia, France, Germany, Iceland, Japan (early 1990s), Sweden, the United Kingdom (many cities from about 1994) and the United States. The theory has been disputed in the UK; the Department for Transport predicts a 50% growth in traffic in the coming 25 years and Stephen Glaister, Director of the RAC Foundation, has suggested that UK traffic will grow again as the economy improves.
The idea that car use would eventually reach a saturation level and stop growing further seems to have been around since the 1930s. It has certainly been used in official traffic forecasting since the 1970s, for example in a UK Government study by Tulpule (1973) which forecast that car ownership would reach its maximum level by about 2010, with car use showing little further growth after that point. It has therefore been of interest that traffic levels, and especially car use per head, seemed to show a distinct slowing after 1989, to a rather stable level from about the mid 1990s, and a decline at the national level since about 2008. The decline may have started much earlier in the bigger cities and towns, as reported in Local Transport Today, a professional transport journal in the United Kingdom that the number "peak car traffic" entering Britain's town and city centres during the morning peak hours had declined significantly over the previous ten years; of 21 areas studied all except Leeds had seen falls. Traffic into London had fallen 28% between 1994 and 2003 when the London congestion charge was introduced and a further 12% by 2004. Inbound car trip into Birmingham during the morning peak period had fallen by 29% between 1995 and 2003.
In a series of international comparisons starting in 1993 and continuing until his death in 2011, the American researcher Lee Schipper and his colleagues noted that car traffic growth had slowed or ceased in a number of developed economies. In December 2008, Puentes, R. and Tomer reported for the The Brookings Institution that total vehicle miles traveled in the USA began to plateau in 2004 and fell in 2007 for the first time since 1980. Per capita driving was observed to follow a similar pattern. A particularly influential series of articles was published by David Metz (2010, 2012), who had formerly been the Chief Scientist of the UK Department of Transport, suggesting that the Department's forecasts of growth were erroneous because in the UK a saturated peak level had already been reached.
The preceding studies mostly discussed the first interpretation of 'peak car', namely that growth had ceased with the achievement of a stable saturation level. Between June and September 2010 a series of articles were published by Phil Goodwin in the UK professional transport press on the second hypothesis, namely that the observed plateau might be the early signs of a reverse to a declining trend. These articles were later compiled and updated in a journal article by Goodwin (2011). David Metz, of University College London noted that, in the UK, "peak car use came and went at least 15 years ago, when none of us noticed". The idea was then discussed in a paper published in a November 2010 by Millard-Ball and Schipper. They presented data confirming the trend in cities in eight nations: United States, Canada, Sweden, France, Germany, the United Kingdom, Japan and Australia. A further article supporting the theory held true in Australia was published by researchers Newman and Kenworthy in June 2011.
Proposed causes 
It is not known why it's happening but multiple interrelated reasons are being theorized, for example by Newman: and in a special issue of the journal World Transport Policy and Practice edited by Melia. Suggested reasons include:
- Travel time budgets, a theoretical psychological limit suggesting a long term constraint on the amount of time people allocate to travel of about one hour a day. Studies using this concept (albeit not always defined in the same way) have included those of Zahavi (1974), Mogridge (1983) and Metz (2010) who suggested that saturation would naturally follow from the observation that access to destinations increased with the square of speed, but was offset by the tendency for each additional choice of destination to offer less and less extra benefit. A version was suggested by Marchetti, sometimes called 'the Marchetti Wall'; when cities become more than "one hour wide," they stop growing or they become dysfunctional, or both.
- The growth of public transport
- The reversal of urban sprawl
- The growth of a culture of urbanism
- The aging of cities
- The rise in fuel prices
- Successful application of traffic-reducing policies such as pedestrianisation of city centres, traffic calming, parking control, congestion charging
- Reallocation of road capacity away from cars resulting in Disappearing Traffic
- Cultural shifts especially among young people for whom acquisition of a driving license is now seen less as a key rite of passage into adulthood, and is reflected in recent reductions in the propensity of young people to acquire driving licenses. (citation to follow).
- The growth of various sorts of e-commerce (tele-shopping, conferences, etc.) and mobile phone or computer based social networks which may have reduced a proportion of car-based movement, such that the 'love affair with the phone' has replaced the 'love affair with the car' for a proportion of the population.
The proposition has been disputed in the UK; in December 2010 Stephen Glaister, the Director of the RAC Foundation, suggested that total traffic has grown more or less as a straight line since the 1950s and such growth will recommence when economic conditions improve; in 2011 the UK Department for Transport predicted a 50% growth in traffic in the coming 25 years.
- Japan 
- United Kingdom
- United States
Declines of total 'vehicle kilometers traveled' (vkt) in selected cities as reported in the research:
|USA||Atlanta||-10.1%||from very high levels 1995|
|USA||Houston||-15.2%||from very high levels 1995|
See also 
- Tulpule, A. H. (1973). Forecasts of vehicles and traffic in Great Britain 1972 revision, Report LR543. Crowthorne, UK: Transport and Road Research Laboratory.
- "Peak car traffic dropping in city centres, LTT survey reveals". Local Transport Today. 7 April 2006. "The number of cars entering Britain's town and city centres in the morning peak hours has declined significantly in the last ten years, according to analysis of 21 urban areas conducted by LTT.... The number of people entering central London by car during the morning peak hours (0700-1000) has fallen by over 40% since 1994 and had already declined by 28% prior to the introduction of the congestion charge in 2003. Birmingham saw the number of inbound trips by car during the morning peak period fall by 29% between 1995 and 2003."
- Schipper, Lee; Steiner R, Figueroa M J, Dolan K (1993). "Fuel prices and economy. Factors affecting land travel". Transport Policy ! (1): 1–22.
- Schipper, Lee (2011). "Automobile use, fuel economy and CO2 emissions in industrialized countries: Encouraging trends through 2008?". Transport Policy 18: 358–372.
- Puentes, R. and Tomer, A. (2009). "The Road Less Travelled: An Analysis of Vehicle Miles Traveled Trends in the U.S. Metropolitan Infrastructure Initiatives Series". Brookings Institution, Washington DC. "An analysis at the national, state, and metropolitan levels of changing driving patterns, measured by Vehicle Miles Traveled (VMT) primarily between 1991 and 2008, reveals that: Driving, as measured by national VMT, began to plateau as far back as 2004 and dropped in 2007 for the first time since 1980. Per capita driving followed a similar pattern, with flat-lining growth after 2000 and falling rates since 2005. These recent declines in driving predated the steady hikes in gas prices during 2007 and 2008."
- Metz, David (2010). "Saturation of demand for daily travel". Transport Reviews. 30 (5): 659–674.
- Metz, David (2012). ") Demographic determinants of daily travel demand". Transport Policy. 21(1): 20–25.
- Goodwin, P. (25 June 2010). "What about ‘peak car’ – heresy or revelation?". Local Transport Today. "Rail, bus and tram use all peaked and then declined, so why do so many people assume that car use will either keep rising indefinitely or reach saturation and a ‘steady state’ condition?"
- Goodwin, P. (23 July 2010). "Thoughts on peak car – part two". Local Transport Today. "‘Peak car’ is the idea that car use may not saturate, but turn down. In Part One in June I discussed the experience of rail use after 1918, and road public transport use after 1950, where this happened. In Part Two in July I considered what sort of evidence could distinguish between the identical-looking saturating curve and one about to turn down."
- Goodwin, P. (20 August 2010). "Peak Car – part three: the evidence". Local Transport Today.
- Goodwin, P. (17 September 2010). "Peak Car – part four: the policy implications". Local Transport Today.
- Goodwin, Phil (2011). "Three Views on 'Peak Car'". World Transport Policy & Practice. 17 (4).
- "Car use peaked in London fifteen years ago". Local Transport Today. 9 July 2010. "as far as London is concerned, peak car use came and went at least 15 years ago, when none of us noticed. Transport for London’s most recent Travel in London report records a steady decline in private transport’s share of trips since at least 1993 (then 50%, 41% in 2008). Correspondingly, public transport’s mode share has risen from 24% to 33%, while walking and cycling have been steady at about 25%. Historically, car use has invariably increased as incomes have risen. So it is remarkable that this trend has gone into reverse in London, a prosperous world city with a growing population."
- Millard-Ball, A. and Schipper, L. (18 November 2010). Are We Reaching Peak Travel? Trends in Passenger Transport in Eight Industrialized Countries (Volume 31, Issue 3, 2011). Transport Reviews.
- Peterson, G. (5 January 2011). "Peak travel?". Resilience Science.
- Herrman, J. (3 January 2011). "Has passenger travel peaked?". SmartPlanet.
- Newman, P. and Kenworthy, J. (June 2011). "Peak Car Use’: Understanding the Demise of Automobile Dependence". World Transport, Policy & Practice (Curtin University Sustainability Policy Institute) (Volume 17.2).
- Melia (Guest Editor), Steve (2011). "Special Issue on 'A Future Beyond the Car'". World Transport Policy and Practice. 17 (4).
- Zahavi, Yacov (1974). Travel Time Budgets and Mobility in Urban Areas. Washington DC, USA: US Department of Transportation.
- Mogridge, M J M (1983). The Car Market: A study of the statistics and dynamics of supply-demand equilibrium. London: Pion. ISBN 0-85086-085-7.
- "'Peak Car Use' Shows a Rational Public". NationalJournal Transportation. 18 July 2011.
- Glaister, Stephen. "Evidence to the transport select committee inquiry on transport and the economy, questions 430-460, House of Commons 2 Mar 2011.". UK Parliament. Retrieved 2012-04-28.
- "DfT rejects ‘peak car’ hypothesis and predicts return to traffic growth". Local Transport Today. 16 March 2012. "After decades of relentless growth the last ten years have seen road traffic volumes first stabilise and then decline. But the DfT believes this is just a temporary blip and that growth will soon resume... ROAD TRAFFIC volumes in England are likely to grow by almost 50% over the next 25 years, according to the DfT’s new National Road Traffic Forecasts (NRTF). The headline forecast is that road traffic will rise from 261.2bn vehicle miles in 20101 to 375.6bn in 2035. This 44% growth is a central estimate, between the low growth of 34% (to 349.8bn miles) and the high growth of 55% (to 405bn miles)."
- Pearce, Fred (16 Aug 2011). "The end of the road for motormania". New Scientist. Retrieved 25 Apr 2012. "Japan peaked in the 1990s. They talk there of "demotorisation". The west had its tipping point in 2004. That year the US, UK, Germany, France, Australia and Sweden all saw the start of a decline in the number of kilometres the average person travelled in a car that continues today. In Australia, car travel peaked in every city in 2004 and has been falling since"
- Andrew Pendleton (12 April 2011). "Has Britain reached "peak car"?". NewStatesman.
- "Is this the end of the car?". The Independent. 20 May 2011.
Further reading 
Article listed below are in chronological order.
- Impact of Baby Boomers on U.S. Travel, 1969-2009 AARP Public Policy Institute, November 2012.
- The future of driving - Seeing the back of the car: In the rich world, people seem to be driving less than they used to, The Economist, September 22, 2012.
- Due diligence, traffic forecasts pensions Goodwin, P. Local Transport Today (subscription) 13 April 2012
- Traffic Growth: Modelling a Global Phenomenon, Department of Infrastructure and Transport, Australian Government, March 2012.
- Trafﬁc Growth in Australia, Department of Infrastructure and Transport, Australian Government, March 2012.
- A Future Beyond the Car? World Transport, Policy & Practice Volume 17.4 January 2012
- Government funding for council road building criticised as ‘peak car’ phenomenon debated Local Transport Today (subscription) 21 October 2011
- We Are Approaching Peak Car Use
- Peak car theory ‘a risky basis for policy’ Local Transport Today (subscription) 3 June 2011
- Peak car? The international dimension Goodwin, P. Local Transport Today (subscription) 3 June 2011
- Economic restructuring could explain the slowdown in car use Sandy Ochojna Local Transport Today (subscription) 20 November 2009