Transport, urban form and health

The Public Health Advisory Committee (PHAC) has released a very interesting study into the linkages between urban environments and wellbeing, entitled Healthy Places, Healthy Lives: urban environments and wellbeing. During my university studies I did quite a lot of research into what we call “Health Geography” – looking at how different environments affect different health outcomes. There are obvious linkages, like if you live in a polluted area or on a damp house then chances are you’ll have poorer health on average than someone elsewhere, but other areas of linkages are a bit more complex, and interesting. Particularly when we look at analysing the links between urban form and health outcomes.

Here’s an interesting extract from the PHAC’s study:

In high-income countries such as New Zealand, advances in engineering during the past 50 years have reduced physical activity in daily urban life. People drive to work, school or the shops, work is more sedentary than it was for people in previous generations, and recreation is also increasingly passive. Many of New Zealand’s urban areas, built over the past 50 years in response to population growth, were planned around these advances in engineering. Such neighbourhoods often have poorly connected street networks (for example, cul-de-sacs rather than grid-like streets) and low-density housing that is beyond walking distance to shops, workplaces and public transport.

International and New Zealand research suggests that the way we have been designing and planning our cities over recent decades is leading to some unintended negative consequences for health. Planned primarily around cars, these neighbourhoods are not conducive to physical activity for either recreation or active transport. In the resulting environments, there are fewer opportunities for social interaction, more motor vehicle emissions contributing to poorer air quality, and greater risk of road traffic injuries.

There’s certainly nothing here that we didn’t know already, but what this report does is put a few numbers on these effects:

• Physical inactivity accounts for almost 10 percent of New Zealand’s 20 leading causes of death. It is a contributor to obesity and type 2 diabetes, which together cost the health system over $500 million per year.
• The social cost of pedestrian injuries and fatalities is estimated to be $290 million per year (based on 1996–1999 averages). The social cost of all road traffic injuries was estimated to be $3.7 billion in 2008.
• Air pollution accounts for over 3 percent of New Zealand’s 20 leading causes of death. Motor vehicle pollution, which is more common in urban areas, causes an estimated 500 deaths per year, an extra 540 cases of bronchitis, and an extra 250 hospital admissions for acute respiratory and cardiac conditions in New Zealand in adults over 30 years. Vehicle emissions can cause or exacerbate respiratory and cardiac illness, which costs the health system and economy an estimated $415 million per year.

It’s not inconceivable, nor illogical, to wonder whether the Ministry of Health should be funding the construction of cycleways around our major cities.

The study also looks at what overseas cities have done to make themselves “more healthy”:

Many of the world’s most notable cities have been planned to promote healthy, active and social living. Florence’s abundance of cafés encourages walking and social interaction. Copenhagen’s support for cycling paints a new picture of ‘commuter traffic’. New York City’s intricate public transport system efficiently carries millions of passengers every day, and its numerous public parks provide opportunities for recreation and social cohesion.

Some of these features have historic roots, as in Florence and New York City. Others involve a deliberate shift in their shape and form. In these cases, leaders have recognised that developing multiple transport modes, opportunities for walking and cycling, and mechanisms for social interaction bring ‘co-benefits’ in terms of the environment, tourism, business, health and society. The changes undertaken in Copenhagen and Portland, Oregon provide two examples of this kind of leadership.

In Denmark, cycling to work plummeted between 1950 and 1975. Then the 1970s oil crisis prompted the Government to invest in cycling and public transport infrastructure. Policies included establishing cycle lanes and paths, modified intersections, traffic signals that prioritised cyclists, and traffic calming measures. Private car use was discouraged through parking fees, taxes and tough driving tests. These changes have meant that one-third of Copenhagen residents now cycle to work, and there has been a 25 percent drop in cycle accidents. The Government is investing another US$16 billion in high-speed intercity trains, light rail and city bicycle lanes. The aim is to increase the proportion of Copenhagen commuters cycling to work to 50 percent by 2020.

In the 1970s Portland, Oregon was threatened with a deteriorating urban centre, degraded housing and poor air quality. Through both city and state leadership in urban planning, the Government prioritised urban regeneration, the expansion of public transport, walking and cycling infrastructure, and integrated urban development and transport planning. City authorities turned down a proposed bypass highway in favour of light-rail and public transport-oriented development when they realised that the latter would produce significantly fewer vehicle miles travelled and lower levels of congestion. These efforts have led to positive outcomes for health, the environment and the economic growth of the city. The city is rated as one of the most walkable and cycleable in the United States. Greenhouse gas emissions decreased by 13 percent per year from 1990 to 2003. Walking traffic led to more retail spending, and the regenerated city became a focal point for business, attracting skilled workers, residents and tourists.

The efforts of Copenhagen and Portland highlight the changes to cities that leadership and a focus on healthy urban design can achieve. Many urban areas are developing compact, liveable communities that reduce urban sprawl, increase transport options, create a sense of community and place, and preserve natural resources. Different sectors and traditions have converged to advocate for these changes in response to climate change, resource depletion, rising greenhouse gas emissions, obesity, excessive water use, water and air pollution, traffic congestion, and social isolation. They have found that these changes also create more foot traffic and retail spending and have lower public service and infrastructure costs per capita.

Public health leaders have been among those gathering evidence about urban form and advocating for such changes. The Healthy Cities movement of the World Health Organization (WHO) has focused increasingly on urban planning. The recent report produced by the WHO and the Commission on Social Determinants of Health highlights improved living conditions (including health-focused urban governance and planning) as one of three overarching recommendations to improve health equity.

A number of recommendations are made:

Looking at how we might structure a public transport network to better promote good health outcomes, I think one gain through “The Network Effect” that is not particularly well explored is that having a sparser, but higher quality, public transport network means that people are likely to, on average, walk more. If my bus stop is a 5 minute walk away, but the bus only comes every 20 minutes, chances are I’m going to spend 5 minutes walking to the bus stop and then at least 5-10 minutes waiting for the bus (I’ll make sure I get there early so I don’t miss it). On the other hand, if my bus stop is an 8 minute walk away, but the buses come every 5 minutes, then chances are I’m only going to be spending a couple of minutes waiting for my bus, more than making up the extra time spent walking. In other words, on average people will spend more time walking and less time waiting – which is probably a better health outcome without being a worse public transport outcome.

If you throw into the mix the ability to ride your bike to a public transport stop/station, and make it easy to do so (bike racks etc) then once again you’re tapping into health benefits as well as transport benefits. It makes me wonder whether health effects should be a negative in the cost-benefit analysis of motorways.

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