Peak car (also peak car use or peak travel) is a hypothesis that motor vehicle distance traveled per capita, predominantly by private car, has peaked and will now fall in a sustained manner. The theory was developed as an alternative to the prevailing market saturation model, which suggested that car use would saturate and then remain reasonably constant, and GDP based theories which predict that traffic will increase again as the economy improves, linking recent traffic reductions to the recent economic downturn.
The theory was proposed following reductions, which have now been observed in Australia, Belgium, France, Germany, Iceland, Japan (early 1990s), New Zealand, Sweden, the United Kingdom (many cities from about 1994) and the United States. Traffic into London fell by 28% between 1994 and 2003 (prior to the introduction of the London congestion charge). A study by Volpe Transportation in 2013 noted that average miles driven by individuals in the United States, has been declining, from 900 miles per month in 2004 to 820 in July 2012, and that the decline had continued since the recent upturn in the US economy.
A number of prominent academic has written in support of the theory, including Professor Phil Goodwin, and then Profeesor David Metz, a former Chief Scientist of the UK Department of Transport. The theory is however disputed by the UK Department for Transport, which predicts that road traffic in the United Kingdom will grow by 50% over the coming 25 years and Professor Stephen Glaister (Director of the RAC Foundation) who suggest that traffic will start increasing again as the economy improves. Unlike peak oil, a theory based on a reduction in the ability to extract oil due to resource depletion, peak car is attributed to more complex and less understood causes.
The idea that car use would eventually reach a saturation level and stop growing further seems to have been around since the 1930s. In Traffic in Towns, a report produced in 1963 for the UK Ministry of Transport, Professor Sir Colin Buchanan suggested that traffic would saturate early in the 21st century. 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.
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.
'Peak car' theory
The 'peak car' hypothesis was proposed after declines in traffic were observed from the mid 1990s in some places and at a national level since about 2008. 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 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.
Between June and September 2010 Professor Phil Goodwin published a series of articles in the UK professional transport press suggesting that data showed not merely a plateau in vehicle miles driven but rather a decline in overall automobile usage per capita. These articles were later compiled and updated in a journal article by Goodwin, published in 2011.
David Metz, of University College London and former Chief Scientist of the UK Department of Transport noted that "peak car use came and went [in the UK] at least 15 years ago, when none of us noticed". He then published articles in 2010 and 2012 suggesting that the Department's forecasts of growth were erroneous because in the UK a saturated peak level had already been reached.
In November 2010 by Millard-Ball and Schipper presented data confirming the trend in cities in eight nations: United States, Canada, Sweden, France, Germany, the United Kingdom, Japan and Australia. Newman and Kenworthy published an article in June 2011 suggesting that the effect was also valid for Australia.
There is speculation about causes of a decline in automobile usage. Analysts such as Newman as well as views expressed in the journal edited by Melia entitled World Transport Policy and Practice point to various interrelated causes. Factors 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. For example, train travel in the United Kingdom has been undergoing a renaissance, according to one view.
- The reversal of urban sprawl and other population shifts from suburbs to cities.
- The growth of a culture of urbanism.
- The aging of cities.
- Rising fuel prices.
- Increasing costs of automobile ownership, including costs for insurance and parking.
- Traffic-reducing policies such as the "pedestrianisation" of city centres, traffic calming, parking control, congestion charging.
- Proliferation of different ways to own and rent vehicles, such as Streetcar, Zipcar, and Whipcar, as well as other options for car sharing.
- Reallocation of road capacity away from cars towards bikes and pedestrian traffic 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. One report suggests there has been a shift in notions about status: the car is no longer a "big prestige item" as in previous decades. For millennials and digital natives, there is less focus on ownership of things, especially big-ticket items such as cars. There is a report that young people see cars as "unnecessary pricey" appliances.
- Legal restrictions; for example, restrictions on teenagers seeking driver's licenses.
- Demographic changes; for example, baby boomers drive less as they age, according to one view.
- Economic factors, particularly unemployment.
- Saturation of demand in the sense that there has been a "levelling-off" of possible places to travel to by car. According to this view, when road networks were expanding, there were numerous options of new places to drive to, but as road networks have generally stopped expanding, the demand for increased car travel has become saturated.
- Growth of e-commerce such as tele-shopping, conferences, and mobile phone or computer-based social networks. According to this view, these developments have reduced the need for travel by car, such that the 'love affair with the phone' has replaced the 'love affair with the car' for a proportion of the population, and that widespread use of cellphones and Skype meant there was less need for in-person visits. However, a contrasting view suggested that e-commerce was not a substantial factor explaining less car travel in the United States. Still, countries with higher use of the Internet correlated with fewer 20—24 year olds getting drivers' licenses.
One analyst explained about changing attitudes of young people:
Virtual contact through electronic means reduces the need for actual contact among young people ... Furthermore, some young people feel that driving interferes with texting.
Another elaborated about the saturation of demand hypothesis:
They say as we get richer, we'll want to travel more. There's no limit. Our hunch was that this might not be the case. ... The data that we have shows fairly clearly that the growth in travel demand has stopped in every industrialised country that we looked at.
The proposition that car usage has peaked has been disputed regarding vehicle usage in the United Kingdom. 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. In addition, a corroborating view by Paul Watters suggested that car usage will continue to be important in Britain, and that there won't be “shattering change” by 2020.
- Japan 
- New Zealand
- South Korea
- United Kingdom
- United States
- Note, in China there is a forecast of tremendous growth in car ownership and travel, although there is also greater awareness of environmental issues as well as issues of inequality between car-owners and non-owners.
Declines in specific countries
The city of Hamburg in its so-called Green Network Plan, is considering ways of phasing out automobile traffic in the city center over the next two decades by increasing public transportation and adding special routes for bicyclists and people on foot.
One report suggested driving in the United Kingdom has been declining since 1990. The percent of 17-20 year olds with drivers licenses declined from 48% during the early 1990s to 35% in 2011, according to one report. Traffic by cars and taxis has declined since 2007. One report suggested renewed growth in train travel, such that there was a "rail renaissance" underway. The city of London has been experiencing a fall in the number of cars on the roads.
A report in Time Magazine suggested Americans are "driving less and less each year." It noted that fewer Americans were "commuting solo" to work. Road congestion nationwide declined by 27% in 2011. There is some evidence of a generational shift. For example, one 24-year old with a car moved to Washington, D.C. for work purposes but did not bring her car, and she explained:
I don't need (my car). My apartment is just over a mile from my office, so I walk every day... I think I might give it to my parents...
According to transportation consultant Roy Kienitz, driving habits began to change in 2004 before the 2007-2010 recession started.
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|
- Brad Tuttle, Sept. 25, 2012, Time Magazine, What Happens When We Reach ‘Peak Car’?, Accessed Sep. 1, 2013
- Paul A. Eisenstein of The Detroit Bureau, August 30, 2013, MSNBC, Americans drive less even as economy rebounds, Accessed Sept. 1, 2013
- Tulpule, A. H. (1973). Forecasts of vehicles and traffic in Great Britain 1972 revision, Report LR543. Crowthorne, UK: Transport and Road Research Laboratory.
- 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.
- "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."
- 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."
- 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."
- 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.
- 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. doi:10.1080/01441647.2010.518291.
- 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.
- The Guardian, 28 January 2013, High-speed rail: tracks through the haze: A £32bn investment in HS2 means the government is pressing full-steam ahead with its far in the future transport policy, Accessed Sept. 1, 2013
- Julia Pyper and ClimateWire, Scientific American, Has the U.S. Reached "Peak Car"? Traffic is easing as more Americans are deciding to drive less, sell their cars or not buy one at all, Accessed Sept. 1, 2013
- Alex Rayner, 25 September 2011, The Guardian, The end of motoring: Young people today would rather have the latest smartphone than a flashy car. And the number of them who can drive is plummeting. Is Britain's love-affair with the car really over?, Accessed Sept. 1, 2013
- 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.
- Tania Branigan, 14 December 2012, The Guardian, China and cars: a love story -- China is now the world's biggest market for new cars. Its motorway network will soon rival America's. But while the rich splash out on Porsches and Ferraris, resentment is growing among the have-nots, Accessed Sept. 1, 2013
- Paul A. Eisenstein, CNBC, 26 Jan 2014, A ban on autos? Major cities consider going carless, Accessed Jan. 25, 2014
- 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.
- United Kingdom
- Metz, David (2014). Peak Car: The Future of Travel. Landor LINKS Apollo House, London. p. 114. ISBN 978-1-899650-75-0. (e-book edition)
- Due diligence, traffic forecasts pensions Goodwin, P. Local Transport Today (subscription) 13 April 2012
- Government funding for council road building criticised as ‘peak car’ phenomenon debated Local Transport Today (subscription) 21 October 2011
- Economic restructuring could explain the slowdown in car use Sandy Ochojna Local Transport Today (subscription) 20 November 2009
- United States
- Has Motorization in the U.S. Peaked? , Michael Sivak, University of Michigan, Transportation Research Institute (UMTRI)
- Has Motorization in the U.S. Peaked?, June 2013.
- Part 2: Use of Light-Duty Vehicles, July 2013.
- Part 3: Fuel Consumed by Light-Duty Vehicles, November 2013.
- Part 4: Households without a Light-Duty Vehicle, January 2014.
- Has Motorization in the U.S. Peaked? Part 5: Update through 2012, April 2014
- Transportation in Transition - A Look at Changing Travel Patterns in America’s Biggest Cities, U.S. PIRG Education Fund and the Frontier Group, December 2013.
- Has Growth in Automobile Use Ended?, John A. Volpe National Transportation Systems Center, August 2013
- The End of Car Culture, The New York Times, 29 June 2013.
- Impact of Baby Boomers on U.S. Travel, 1969-2009 AARP Public Policy Institute, November 2012.
- International scope
- Woes of Megacity Driving Signal Dawn of ‘Peak Car’ Era, Bloomberg News, February 2014.
- Long-run Trends in Car Use, International Transportation Forum (ITF) Round Tables, No. 152, OECD, 2013
- 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, 22 September 2012.
- A Future Beyond the Car? World Transport, Policy & Practice Volume 17.4, January 2012
- 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