Fewer cars, healthier citiesBMJ 2019; 367 doi: https://doi.org/10.1136/bmj.l6605 (Published 18 December 2019) Cite this as: BMJ 2019;367:l6605
- Mark Stevenson, professor of Urban Transport and Public Health
- Transport, Health and Urban Design Research Lab, University of Melbourne, Melbourne, VIC 3010, Australia
- Correspondence to: M Stevenson
Globally, substantial change in population demographics is afoot with 65% of the world’s population estimated to live in cities by 2050.1 This unprecedented urbanisation will place considerable strain on city infrastructure including water and energy utilities, schools, hospitals, and transport systems, thereby reducing economic productivity.2 The exponential growth of our cities—referred to as the “urban age,”3 could reduce a city’s resilience, jeopardise future levels of population health,4 and compromise residents’ quality of life.5
The urban age brings a level of uncertainty surrounding the structure and design of future transport systems. It also raises uncertainty about the health implications of new, automated or hybrid systems, and how best to operate these systems safely. What we do know is that private use of motor vehicles is unlikely to remain the predominant feature of road transport.
The health consequences of our current system have been substantial. Each year, an estimated 1.35 million people globally die from road traffic incidents 6 while 4.2 million people die as a consequence of air pollution.7 Particulate pollution (50% of which comes from cars) reduces life expectancy by 1.8 years per person.8
The harms associated with private use of motor vehicles extend beyond road traffic incidents and respiratory disease to physical inactivity, a leading cardiovascular risk factor for more than one quarter of the world’s population.9 Much has been written on the association between private use of motor vehicles and physical inactivity.10 But the linked paper by Anderson and colleagues11 (doi:10.1136/bmj.l6491) reports that a lottery system for permits enabling Beijing residents to purchase a motor vehicle is associated with declines in use of public transport and physical activity among winners, leading to weight gain.
What this paper doesn’t highlight, however, is the opportunity such a reward system could have in moving rapidly motorising cities across China towards a more sustainable transport system, by restricting the purchase of private motor vehicles. Each year, about 23 million new cars are sold in China12 and transport policies that restrict sales and transition towards more sustainable (and safer) transport systems will not only reduce the burden of disease and injury but also contribute substantially to mitigating climate change.
Cities should embrace urban mobility options that move away from a dependence on private motor vehicles and towards sustainable transport systems that provide equitable access to people living either in the city centre or in outer urban areas. Transport policies can support this approach by incentivising walking, cycling, and public transport while reducing subsidies for private vehicles. Many cities have already achieved substantial declines in traffic.13 For example, in Zurich, Switzerland, more than half of the vehicle kilometres travelled are now undertaken by active means (that is, walking or cycling), and a further 19% are travelled on public transport; only 29% of trips are undertaken using cars.14
Recent evidence415 supports a modal shift towards alternative transport that includes a mix of public transport, cycling, and walking, and reports the health benefits associated with transferring kilometres travelled from private motor vehicles to public transport. For example, Kwan and colleagues15 estimated that the introduction of two rapid transit lines in Kuala Lumpur, Malaysia, would shift travel from private to public transport, leading to substantial reductions in road deaths and serious injuries, with additional benefits for health and the environment.
The health consequences of rapid motorisation include increased rates of cardiovascular disease, diabetes, respiratory disease, some cancers, and road trauma.16 Transport policies have a direct influence (both positive and negative) on the health of city residents. Importantly, land use decisions influence population health, by determining available transport options and therefore travel choice.4
Sprawling residential development patterns, which dominate many cities around the world, limit the ability of children and adults to walk or cycle to school and work.17 Low density housing found in such areas makes the cost of public transport prohibitive, produces a reliance on private motor vehicles, and increases residents’ exposure to the well known risks associated with traffic speed and volume, vehicle emissions, and physical inactivity.18 Urban and transport planning policies that optimise the health of future cities is an increasingly urgent priority.
Competing interests: I have read and understood the BMJ Group policy on declaration of interests and declare the following interests: None. MS is funded by a Fellowship from the Australian National Health and Medical Research Council APP1136250.
Provenance and peer review: Commissioned; not peer reviewed.