Speed does not -- in and of itself -- somehow create more collisions. What makes a collision is a difference of relative speed.

There is a substantial difference in how public policy would address head injuries involving: 1) solo bicyclist rider error, 2) stationary motor vehicles, 3) moving motor vehicles, 4) pedestrians, 5) collision with other bicyclists, or 6) stationary object collisions.

From my list earlier, absolute speed would tend to exacerbate scenarios 1, 2, 4, and 6. But would make little difference to scenario 3, and scenario 5 would depend on the speeds of other bicyclists. My analysis points out that if scenario 3 is what has been drastically increasing in the past decade -- which is corroborated by the Oregon study linked earlier -- then no, speed is pretty much irrelevant. Being struck by a motor vehicle driver making a turn is going to be bad, no matter what speed the bicycle, ebike, or motorcycle was going.

What I cannot show -- nor can anyone show otherwise -- is the prevalence of those scenarios in proportion to overall collisions. We simply have insufficient data, which should be a call to action for better information from collision investigations.