@Lyle We do have bollards in many places, especially public transport hubs. But you can't put them everywhere.
@LouisIngenthron Something additional we do in Charlottesville is block off crowded areas with large city Parks trucks. This is expensive, but so far we have had good experiences with this approach. As you can imagine we take this seriously.
@LouisIngenthron we would have to do what other countries do https://en.wikipedia.org/wiki/Bollard