Well, I assume they err on the side of caution "too much". Sensible guidelines would be for self-driving cars to be approved by regulatory guidelines when they

Well, I assume they err on the side of caution "too much". Sensible guidelines would be for self-driving cars to be approved by regulatory guidelines when they cause less accidents (and less severe at that) on average. But currently a single accident could cost a company its license to test on public roads, and that is basically a death sentence.