Surviving Oxford Road

Posted on June 15, 2012


Here’s a confession…I cycle.

That’s just what I do.  It’s probably genetic, given that I am Dutch, so I cannot help it. I also cycle in Manchester; very stereotypical according to my friends, and also not one of my brightest ideas apparently. To date I have only been run over once, avoided a handful of near accidents and have been shouted at for things involving the words “eco-maniac” , “unemployed scum”, or similar flattery starts of a merry discussion about who owns the road (It turns out that armouring yourself with a ton of metal for many people here implies you are stronger and thus people should move out of the way when you arrive. A bit like the knights in the good old days I suspect…).

Not only do I cycle, cycling to work takes me back and forth on Oxford Road, which is no mean feat:

Oxford Road is currently one of Manchester’s key commuter roads and officially the busiest bus route in Europe, with more than 100 buses an hour.

So when it comes to risk of accidents and exposure to traffic pollution, I play major league!

Work by Jeroen de Hartog and colleagues (link) published in Environmental Health Perspectives (I admit, some time ago, but that doesn’t make it less relevant) had attempted to estimate the health benefits of cycling and evaluate whether the benefits would outweigh the risks. So does my continuing use of the bicycle remain to be a good idea, or would it be better to buy a bus pass, or a car? More generally, since about 50% of all car trips are less than 7.5 km many people could, at least in theory, use a bike instead. And if they would, would that be a good idea?

The exposures included in this study were air pollution, traffic accidents and physical  activity while the outcome of interest was mortality (let’s face it; a bus driving over your bike on your way to work is one thing, but a bus driving over me would be seriously inconvenient). They used published data on air pollution exposure during cycling and driving from a large variety of different published peer-reviewed studies in the Netherlands, Denmark, and the UK (well, London and Huddersfield so there’s room for debate on this), and similarly data from a large number of studies in different countries on health effects of air pollution, traffic deaths and on the impact of physical activity on mortality to go into their calculations. So overall, quite thorough (although, of course, one can debate the actual numbers, which therefore was done by a group from Belgium (link) and which did not really change the main conclusions).

Interestingly enough, exposure to air pollution is 1.01 to 1.65 (depending on the specific type of exposure) higher for car drivers than for cyclists on average, but this too some extent is offset by the faster breathing of cyclists. I guess, as a valuable lesson for life, if you relax a bit on your bike and chill out you can add up both of these benefits. Nonetheless, physical activity is good for you and a minimum of 30 minutes of moderate-intensity activity for five days a week, or a tougher workout for shorter time, apparently “promotes and maintains health”. As it turns out replacing your car with a bike for these 7.5 km rides will get you there without too much…for lack of a better word…effort.

So does it add up in the end? Should I keep cycling or should I switch to something more 20st century (i.e. with a big engine)? It turns out that cycling will, in general, extent a person’s life by an additional 3 to 14 months of life, while life lost because of air pollution and traffic accidents were 0.8-40 days and 5-9 days, respectively (on average again, of course). So overall, this cycling business turns out to be a winner with the benefits of cycling compared to using a car being about 9 times larger.

Good news! But hmmm…I don’t live in the Netherlands anymore. I live in the UK. As shown in the extra material available with the paper (link), the risk of fatal traffic accidents for cyclists is substantially higher than in the Netherlands (Having been here for a couple of years now, that doesnt come as a surprise really). De Hartog redid his calculations for cyclists in the UK and found that although the ratio of benefits to costs was smaller, the benefits are still 7 times larger than the risks.

Great, I have made up my mind then. I’ll keep cycling.

Unfortunately, I live in Manchester and I cycle on the busiest bus route in Europe. Data of traffic accidents in Manchester  can be found online (link), while the latest air pollution data on Manchester Oxford Road can be found here (link). Let’s just say there is room for improvement. So all in all, I may need some additional armour (for example, just to keep my head screwed on, they may at least see me before killing me, and legal aftermath) to take me all the way to my retirement.