A major study in Vancouver, BC has looked at the relative safety of biking on various types of infrastructure, by looking at several hundred actual accidents resulting in hospital visits by cyclists over an 18 month period. Vancouver has a lot of different types of bike infrastructure, some of it extremely safe, so it’s a good test bed. Unsurprisingly, busy roads with parked cars and no on-street bike facilities were the most dangerous. Cycletracks (physically separated dedicated on-street bikeways) were an astonishing 90% safer. Interestingly, multi-use paths weren’t all that much safer, despite being preferred by many cyclists.