In Portland – the city I somewhat arbitrarily call home – cyclists own the road. Even through the grey drizzle of a winter morning, a steady throng of bikes surges across the Hawthorne bridge, accounting (.pdf) for 21 percent of traffic. It’s a moving montage of Gore-Tex and spill-proof aluminum thermoses.
Ridership in Portland tripled (.pdf) from 2001 to 2008, and planners continue to develop infrastructure to improve cycling safety. Still, accidents happen; in 2007, the city saw (.pdf) six bicycle fatalities – the highest number on its record for a given year.
It has often seemed to me that urban bike commuters take on an unfair burden, shouldering high risk (not to mention exposure to obnoxious noise and vehicle exhaust) for the good of the collective. Then again, there are obvious individual health benefits to cycling – but do they outweigh the negatives?
A review piece published June 29 in the journal Environmental Health Perspectives addresses that precise question. Thankfully, the answer seems to be yes:
Data synthesis: We quantified the impact on all-cause mortality when 500,000 people would make a transition from car to bicycle for short trips on a daily basis in the Netherlands. We have expressed mortality impacts in life years gained or lost making use of life table calculations.
For the individuals who shift from car to bicycle, we estimated that beneficial effects of increased physical activity are substantially larger (3 – 14 months gained) than the potential mortality effect of increased inhaled air pollution doses (0.8 – 40 days lost) and the increase in traffic accidents (5 – 9 days lost). Societal benefits are even larger due to a modest reduction in air pollution and greenhouse gas emissions and traffic accidents.
So consider cycling to work; but do it safely. Wear a helmet and take a look at a city bike map before you hit the road.
Photo by kworth30