Just Read: Health Effects of the London Bicycle Sharing System (but does it improve health…)

Bikesharing is a great example of technology used in social innovation. It doesn’t require each individual to be technically inclined, but uses technology to make something basic available to a population, hopefully in a health promoting way.

This is a health impact modelling study, which uses computerized models + assumptions + data to understand the London bicycling sharing (they call it “cycle hire”) system’s impact on disability adjusted life years (DALYs). In my opinion this is a good measure and very “UK” – much more societally focused than what we typically examine in the United States.

They modeled through “medium term changes in physical activity, road traffic injuries, and exposure to air pollution.”

“The” conclusion: some health benefit for men, no evidence of benefit among women, more benefit for older people

“My” conclusion: this is a roadmap for engagement to make sure there is a health benefit

First, the data

  • 7.4 million cycle hire trips examined from April, 2011 to March, 2012 (Hooray for open data!)
  • 71% accounted for by men
  • 78% accounted for by people aged 15 – 44
  • Most trips didn’t replace car, van, taxi, motorcycle (6%)
  • Much higher proportion of cycle fatalities among women compared to men, involving heavy goods vehicles (15 women vs 7 men, despite women accounting for 30% of cycling time from 2005-2011)

As if to underscore the last point, the first cycle hire fatality occurred in 2013, after the analysis period. The second fatality occurred in February 2015. Both victims were women, and involved heavy goods vehicles.

Second, the analysis

Comparison of walking and bicycling in Washington DC 0976

Bike sharing needs to replace more car trips than walking to result in better health (View on Flickr.com)

  • Cycle hire users are younger (97% under 60), and therefore the benefits of preventing physical activity-associated diseases are not going to be realized in the next 10-15 year period
  • Cycle hire users are slightly more physically active overall, but because they mostly replace walking and public transport, the effect isn’t as great as it could be. Still, a little bit more physical activity across a population results in important changes.
  • Cycle hire users are less likely to be exposed to pollution compared to being near cars or in the underground, but breathe more. Overall the impact is small.
  • Cycle hire recorded injury rates are less than for cycling as a whole, but reporting of injuries may not be accurate. The higher injury rate for women increases the harms relative to benefits if the “background cycling injury rate is used.”

Third, the conclusion, the opportunity for engagement

If you take this very well done analysis a different way – as a recipe, rather than analysis, a great platform for the health system presents itself:

  • Substitute more motor vehicle trips with bicycles
  • Support bicycling for older individuals and increase the average age of cyclists
  • Make streets safer

These are three things that physicians, nurses, and health professionals could absolutely champion as partners to bicycle sharing systems.

The substitution issue could be studied carefully, about whether it’s a person deciding on an individual trip to replace a car or whether they wholesale switch away from motorized vehicles.

An important piece of information embedded within: journey times via cycle hire are reduced by 20%.

Reducing the injury rate to that of the Netherlands, the analysis shows, would dramatically increase the health benefits. And what does the Netherlands do?

In the Netherlands, a comprehensive and well maintained system of cycle tracks, physically protected from fast motor traffic, have helped to make cycling widespread at all ages35 and reduce the risks of injury.

First Street NE Cycle Track Washington DC 0978

The beloved cycle track on 1st Street NE, Washington, DC USA (View on Flickr.com)

Washington, DC is also starting to do this, as you can tell from our beloved 1st Street NE bicycle track.

In thinking about why I want bicycle sharing to succeed, it’s because it represents the changing of our cities to support a more sustainable lifestyle in a very visible way.

With that dream comes responsibility. My understanding is that bike sharing systems operate with very minimal staff and resources, and the amount of hope heaped upon them is probably disproportional to their ability to deliver. And why should they? This is what the health system is for, to leverage technology to improve health. The technology is here, on our streets. Now, let’s go leverage it 🙂 .


Ted Eytan, MD