I like to look at these things in terms of kinetic energy. 100mph is roughly 100x more KE than at 10mph. Assume I hit a car with enough energy to break my leg

I like to look at these things in terms of kinetic energy. 100mph is roughly 100x more KE than at 10mph. Assume I hit a car with enough energy to break my leg and the car's windshield. This seems plausible at 10mph. Now, we scale this by 2 orders of magnitude. You could cripple lots of people with this thing in one shot. Bollards wont stop a guy with a scooter.