Has the Historical Growth in Car Use Come to an End in Great Britain?
P Jones, University College London, UK; S Le Vine, Imperial College London, UK; J Polak, Imperial College London, UK
Car ownership and use have grown steady in Great Britain over the last half a century, with only occasional interruptions to this long term trend due to short periods of economic recession. Recently, however, the picture has changed ? well in advance of the current global recession ? with evidence of stabilisation in levels of car use nationally. Similar findings have recently been reported in the United States.
The analysis reported in this paper uses data from the GB National Travel Survey, which collects data from around 8,300 households annually, with each household member completing a seven day travel diary. It forms part of a larger study, carried out for the RAC Foundation, to explore changing patterns of car use and car dependence since the publication of a previous report on Car Dependence in 1995.
What the analysis shows is that, while household car ownership has continued to grow, car use per person (driver and passenger combined) has levelled off in Great Britain, both in terms of the car?s modal share of mileage and trips. We observe an increasing rate of growth in the car share of total mileage per person between 1975 and 1995, when it reached 82%, after which there was an inflection and since 2002 the mileage by car has dropped back to around 80%. When measured as a modal share of all trips, growth continues for a longer period until the inflection point is reached in 2002, since when numbers have fluctuated between 63% and 64%. As a consequence, the intensity of use of the average car has declined over time.
At first sight this seems inconsistent with national traffic data, which shows a continual growth in road traffic. However, closer inspection shows that much of this growth has been in light van traffic, and the growth in car traffic has only matched the growth in the adult population in recent years ? so that car traffic per adult has stabilised.
This situation is anomalous in relation to general economic growth, where the historical relationship between GDP and car traffic now seems to have been broken. The paper considers a number of possible explanations for this stabilisation, including changing population demographics, changes in land use provision and transport supply, and the impacts of different policy measures.
The paper raises questions as to whether what we are observing is the saturation of demand for car use, with most people now experiencing their desired levels of mobility, or a temporary equilibrium brought about by significant levels of congestion on the main road network and a land use system that has adjusted to current levels of car based accessibility. Each of these interpretations of the underlying causes has a different set of implications for traffic forecasting and for the future direction of transport policy, particularly in relation to policies to reduce traffic congestion and CO2 emissions, which the paper explores.
Association for European Transport