The third edition of Dr Tim Senior’s crowd-funded Wonky Health column investigates five ways that transport policies affect health.
He says: “I am questioning an unthinking devotion to the car, at the expense of a transport system that enables all groups in a society to join in and contribute to that society.”
Tim Senior writes:
Tony Abbott said before the election that he wanted to be the infrastructure Prime Minister. And, in what is quite a tightening of the dictionary definition of the word, infrastructure now means roads.
Tony Abbott wants to build roads. Public transport can be left to the state governments. This has been less controversial than many other proposals. Nothing to see here, everybody move on.
But what if the way we move ourselves and our goods around has health consequences?
Perhaps our decisions to build roads, tax petrol, construct cycle paths or increase the cost of train tickets have bigger implications than just time spent in a traffic jam.
Transport often comes up as an issue for Aboriginal Medical Services, usually in terms of accessing appointments. I know many of my patients walk everywhere, some cycle, not as a form of fitness drive, but because they have no other choice, no way of getting around.
Could our decisions about transport have effects on our health?
There are five ways in which transport affects our health, all of which have impacts whatever individual choices we make about how we get around. They also impact us differently if we are children, elderly or where we live. These are:
- Accidents and injuries
- Air pollution
- Physical activity
- Social connectedness
- Noise levels
Don’t get hurt – Accidents and injuries
Travelling by car is the most risky form of travel there is, with 40% of those involved not being in a car. Particularly at risk are cyclists, pedestrians and children. We routinely discount this risk – every morning our transport news on the radio will tell us of delays in the city because of a vehicle accident. Imagine our horror if we heard about an aeroplane crash just because it delayed someone else’s flights. The relationship between more roads, more cars and more accidents is more complex, however. Most accidents happen in built up areas, comparatively few on motorways. Those on motorways, however, are more likely to be serious, because of the higher speeds involved. In fact, there is a dose-response relationship between speed and likelihood of accidents – each reduction in speed of 1km/h reduces accidents by 3%. Certainly, preventive policies such as drink-driving legislation and seat belts do a lot to reduce the numbers of accidents, and the effect of them when they do happen – examples of the nanny state not often criticised nowadays! The likely effect of building more roads is to have more cars on the roads, which results in more accidents overall. Those traffic bulletins will be getting longer.
Don’t breathe in – Air pollution
Cars produce air pollution, in the form of tiny particles, which we all inhale, ozone, NO2, and carbon monoxide. (Of course, they also produce carbon dioxide, which contribute to climate change, and affect our health too.) Though it’s not entirely clear what ingredient in this cocktail is responsible for what, we do know that exposure results in more asthma attacks, more hospital admissions, and a short term increase in cardiovascular deaths. Perhaps surprisingly, it seems that those who get the most polluted air are those inside the cars – not the cyclists or pedestrians outside them (or indeed those on the train!). Living near roads with heavy traffic also puts you at higher risk – especially if you are a child. Policies to restrict emissions levels in new cars – that nanny state again – can keep air pollution levels from rising, but ultimately, increasing the number of cars on the road is a good way of delivering air pollution into populated areas at nose height.
Don’t just sit there – Physical Activity
It’s become common knowledge that sitting around is not good for you. We’ve become accustomed to the solution to this being gym memberships and exercise equipment at home. We’ve also become accustomed to failing. Physical activity has become an optional extra, a commodity to be sold, but not part of everyday life. At the same time, we are using petrol to fuel our activity, instead of our metabolism. What if we used walking and cycling as part of our routines to get to work? There is reasonable evidence that doing this has a good impact on health outcomes, such as risk of diabetes. However, it’s not an easy thing to do. It’s only practicable to walk or cycle for shorter journeys, not the traditional city commute. It requires infrastructure, such as safe cycleways and footpaths, bicycle parking. It may also need public transport – as people have to walk a bit at either end – that is convenient and cheap, and takes bikes. At least currently the nanny state is not telling people to exercise more. Instead it’s shouting at people to get in their cars, loudly encouraged by some media!
Don’t go out and play – Social connectedness
Transport is mostly a means to an end. It is what gets you to a place to do something you need to do – work (or find work), see friends, buy food. It is also what gets the tools you need for your work, the coffee you share with friends, and the food you buy, to the places you go to. Overall, transport should improve our social connectedness. However, the car has moved from a social enabler, to being an isolator – allowing us to move to suburban areas without social centres. Small towns are created around the car, with large shopping centres out of town, few footpaths, and no schools, community centres. Traffic volumes and speeds in an area actually affect the number of friends that people living there have. In areas with high speed or high density traffic, people keep to themselves, and stay away from the roadside, using it only briefly, with no social contact. Local transport density also affects the outdoor play of children, such that they spend less time outside, with less physical activity, and less time socialising with other children. It seems a little odd that a nanny state might be a more effective nanny for our children.
Don’t whisper – Noise
Those who seem convinced, despite all the evidence, that wind farms are bad for our health, should perhaps stop tilting at windmills, and look at transport where there is evidence that noise – proper noise, not infrasound – can have adverse effects on health. Noise can cause annoyance, aggression, poor sleep and impaired communication. Its effect is particularly strong in the elderly, those already hard of hearing, and those used to a quiet environment.
Don’t care – equity
Though we are all affected by these issues, we are not affected equally. It’s usually the case that well off suburbs don’t end up with new motorways built through them, and that high volume traffic areas do not have high house prices. Public transport is often geared to the commute, and so serves the Central Business District and other well off areas best. Poor public transport in less well-off areas of a city can exacerbate other equality problems such as food security, or the ability to travel to look for work. Groups such as children are particularly vulnerable to quite a few of the health issues driven by transport.
Don’t get ill – the solutions?
Thinking about the health consequences of transport policy is an unusual thing to do, and perhaps slightly strange. It’s very easy to deposit the whole issue into a large too-hard basket. We’re not used to thinking that non-health policies have health effects – that choosing to build a new road might result in higher hospital costs. It’s also an area where the health effects are complex, and thinking about just one outcome can adversely affect others. I may have come across as being anti-car. I’m not – my family has 2 of them – but I am questioning an unthinking devotion to the car, at the expense of a transport system that enables all groups in a society to join in and contribute to that society – perhaps a workable definition of infrastructure. The evidence is not clear enough to say exactly what needs to be done. If we wait for sufficient evidence, however, we’ve either done nothing at all, or carried on with policies anyway in the absence of any evidence. This is where values come in.
I’m thinking of Sydney now, and imagining a transport system where most people choose a frequent, convenient and cheap public transport system, perhaps funded by those willing to pay for the privilege of travelling in their own metal box on clear roads. (We already have tolls on many of the major roads into Sydney. And the London Congestion Charge has been a controversial success.) I’m imagining social communities walking and cycling safely to socialise with each other.
None of this may be appropriate. I’m certainly not an expert in transport. But in the midst of all this complexity, the final message is simple.
Consider health outcomes in the cost benefit analysis. It leads to better decisions for all of us.
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Further Reading
I have drawn mostly on two reports looking at the evidence on transport and health.
The first was written by the WHO. Though it concentrates mostly on European data and outcomes, the conclusions are more broadly relevant: http://www.euro.who.int/__data/assets/pdf_file/0003/87573/E72015.pdf
The second is a UNSW report looking at the evidence in an Australian context: http://hiaconnect.edu.au/old/files/Impact_of_Public_Transport_on%20Health_in_Australia.pdf
Here’s an example showing it can be done for a particular road project in Australia: http://onlinelibrary.wiley.com/doi/10.1111/j.1753-6405.1995.tb00385.x/abstract;jsessionid=2F4300D1F326CE2F083F2CC9E3B341AB.f02t01?deniedAccessCustomisedMessage=&userIsAuthenticated=false
It’s also been done in Edinburgh: http://www.sciencedirect.com/science/article/pii/S0033350602000021
And in London: http://jech.bmj.com/content/58/3/169.full
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• Tim Senior and Croakey thank and acknowledge all those who contributed to the crowd-funding campaign to support Wonky Health – more details here.
• This link compiles Wonky Health columns.
