"63% of cyclist seriously injured occur in an accident with no other party involved" Is exactly what I said, as 63% is roughly 2/3.

It really matters what kind of cycling is being done with no other party involved. I injured myself only when I was doing "leisure cycling". I did get almost ran over by a dumb college student once during a commute ride, though.

I'm a huge supporter of public transit, but cyclists are a common enemy for everyone: cars, pedestrians, public transit-takers, other cyclists.