[mollmerx]

I agree that doors of parked cars in cities may be a frequent and painful source of cycling accidents. They are not, however, the most dangerous.

The most dangerous source of accidents for cyclists in cities is from passing turning HGVs (trucks) on the inside. The majority of cycling fatalities in London are caused this way every year.

Fortunately these accidents are avoidable through education of both cyclists and drivers, which is more important than wearing a helmet.