I can't speak to the insurance side, but I know that in Boston, the sort of times when a surge goes over 2x are the same sort of times that it's very difficult

I can't speak to the insurance side, but I know that in Boston, the sort of times when a surge goes over 2x are the same sort of times that it's very difficult to hail a cab, let alone expect dispatch to send one if you call. If the weather is bad enough to be at a 2.5x surge, I'd never expect to be able to get a hackney cab here. Other cities may not have this problem.