Big trucks and SUVs are a much bigger problem. But that doesn't mean kids riding around on motorcycles isn't a problem either.

A friend of mine spent a week in the hospital recently after crashing his new e-bike almost immediately after buying it. One interpretation of his accident is that he didn't have some of the right instincts for riding a bicycle at that speed.

I don't actually have a clear sense of the breakdown of risk attributable to the different factors of lack of appropriate cycling infrastructure, lack of appropriate rider training or experience, lack of appropriate rider expectations, or inherent safety or stability problems of some designs. My friend whom I mentioned above said his doctors told him that they had been seeing a lot of patients who'd crashed e-bikes (as well as electric mopeds and electric skateboards) at speeds that produced fairly serious injuries.