When one ton of metal hits you naked at 50kph (the legal speed limit in traffic areas of cities here in France) the acceleration alone can tear or damage your aorta with impressive odds (IIRC about 50% chance). A helmet is an extremely marginal protection.
On a pure energy analysis, I'd rather have cyclists navigate with pedestrians than with cars. The latter result in a basically non-elastic collision transmitting most of the kinetic energy (1T@30~50kph) to the human body (75kg@5~20kph) while the former is much, much more even.
I don't know the state of streets in the U.S but his is especially true in old european cities, where streets are often narrow and there's simply not enough room for both cyclists and cars on the road, especially when cycling is thought of after the fact.
On a pure energy analysis, I'd rather have cyclists navigate with pedestrians than with cars. The latter result in a basically non-elastic collision transmitting most of the kinetic energy (1T@30~50kph) to the human body (75kg@5~20kph) while the former is much, much more even.
I don't know the state of streets in the U.S but his is especially true in old european cities, where streets are often narrow and there's simply not enough room for both cyclists and cars on the road, especially when cycling is thought of after the fact.