Comment by bccdee

No, there are very specific regulations around infrastructure design, including what sorts of curves are safe in bike lanes at which speeds.

The reason that angle is that "sharp" (I don't think it's very sharp tbh) is because cyclists are explicitly not supposed to zoom up onto the sidewalk at 20 miles per hour. That's how you kill someone. If you're going too fast to make a 30-degree turn and avoid crashing, you're going too fast to be on the sidewalk. It's like complaining that the tight curves on a residential street make it unsafe to drive down it at 60mph.

Anyway, the influence of the auto lobby on urban infrastructure is really well-established: https://en.wikipedia.org/wiki/Car_dependency