A major city street with parked cars and no bike lanes is just about the most dangerous place you could ride a bike. All the big threats are there: open car doors, bad parallel parkers, passing cabs and public transit. This is not a particularly novel scientific revelation, although research has found it to be true. Things get more interesting when we compare this bad-biking baseline to infrastructure actually intended to accommodate cyclists.
New research out of Canada has methodically done just this, parsing 14 route types – from that bike-ambivalent major street to sidewalks, local roads with designated bike lanes, paved multi-use paths and protected "cycle tracks" – for their likelihood of yielding serious bike injuries. As it turns out, infrastructure really matters. Your chance of injury drops by about 50 percent, relative to that major city street, when riding on a similar road with a bike lane and no parked cars. The same improvement occurs on bike paths and local streets with designated bike routes. And protected bike lanes – with actual barriers separating cyclists from traffic – really make a difference. The risk of injury drops for riders there by 90 percent.