Road safety experts understand the contribution of speed to the severity and frequency of road crashes. Yet, the impact of speed on health is far more subtle and pervasive than simply its effect on road safety. The emphasis in urban areas on increasing the speed and volume of car traffic contributes to ill-health through its impacts on local air pollution, greenhouse gas production, inactivity, obesity and social isolation. In addition to these impacts, a heavy reliance on cars as a supposedly 'fast' mode of transport consumes more time and money than a reliance on supposedly slower modes of transport (walking, cycling and public transport). Lack of time is a major reason why people do not engage in healthy behaviours. Using the concept of 'effective speed', this paper demonstrates that any attempt to 'save time' through increasing the speed of motorists is ultimately futile. Paradoxically, if planners wish to provide urban residents with more time for healthy behaviours (such as exercise and preparing healthy food), then, support for the 'slower' active modes of transport should be encouraged.
INTRODUCTIONDecreasing the speed of urban transport can have positive impacts on the economy, the environment and health. This paper outlines the main themes of existing research on these impacts and then explores the possibility that there is a more subtle, but no less important, link between speed and health. The paper argues that speed has a cost that can be measured in money and in time. This can produce a paradox whereby 'faster' modes of transport lead to a loss of time. Lack of time, or time pressure, has been identified as an important factor in urban health, due to its negative impact on mental health but also due to its impact on the ability or willingness of people to engage in physical exercise or to avoid fast (junk) food.The arguments about the health impacts of speed apply most clearly to the use of private motor vehicles, and this paper focuses on the health impacts of increasing the speed of cars. However, some of the arguments are also relevant to other highspeed modes. For example, high-speed trains can encourage urban sprawl, the complex negative health impacts of which are outlined below.Tranter is with the School of Physical, Environmental and Mathematical Sciences, UNSW@ADFA, Canberra, ACT, Australia.Correspondence: Paul Joseph Tranter, PhD, School of Physical, Environmental and Mathematical Sciences, UNSW@ADFA, Canberra, ACT, Australia. (E-mail: paul.tranter@adfa.edu.au)
EXISTING UNDERSTANDINGS OF THE LINKS BETWEEN SPEED AND HEALTHSpeed is most commonly seen as a health issue in relation to road crashes. There are several other ways in which the speed of motorised traffic is linked to factors that have clear negative health impacts. Increasing the speed of motorised traffic increases levels of pollution. 1 High car speeds can affect levels of physical activity through reductions in active transport, including children's independent mobility. Local social interactions are disrupted by high...