These are the results of a study by the Center for Research in Environmental Epidemiology in Barcelona, published in the British Medical Journal (The health risks and benefits of cycling in urban environments compared with car use: health impact assessment study).
Bicing, the Barcelona rental bike system, became operational in 2007. By August 2009 182,062 people had registered, 28,251 of which were regular users of the system. The researchers calculated the health benefits, based on the assumption that 90 per cent of the regular users made the same journeys by car in the past.
The negative health effects due to the exposure to air pollution were calculated on the basis of the amount of small particles (<2,5 um) in the air, which is related to mortality. The consequences of traffic dangers were assessed by calculating the risks per kilometre over the past nine years.
For the calculation of the effects of cycling on physical health the study refers to a recently published extensive international study into health impact assessment (HIA) models (Improving health through policies that promote active travel: A review of evidence to support integrated health impact assessment)’.
Overall a reduction by 12.28 lives is calculated for Barcelona as a result of the introduction of Bicing. By far the greatest impact derives from exercising. This lead to a reduction by 12.46 lives. Traffic fatalities (0.03) and air pollution (0.13) have only a limited impact on these data.