Earlier quoted context omitted.
No, I don’t have the data on hand or the time to hunt down studies that may well not exist. That shouldn’t keep people from knowing what they know. City biking regularly gets up to 15 mph. No I don’t have a citation. Falling over the handlebars is likely when coming to a sudden stop. Brain injuries are not going to be rare occurrences in such cases. No I don’t have a citation.
> Falling over the handlebars is likely when coming to a sudden stop. Only if you are riding a bicycle completely unsuitable for commuting or general urban use; like a mountain bike or racing bicycle. Commonly used bicycles in Denmark and the Netherlands look like this: https://omidbikes.nl/wp-content/uploads/mat-zwart-7.jpg Note the handlebars and upright rider position that basically prevent going over the handleba…
Of course, even then, as a teenager I still managed to get myself into some interesting situations a couple of times. But never went over the handlebars :-P