My cycle to work this morning had a top speed of 40kmph (24mph). I was feeling particularly slow this morning and am only just getting back into cycling. I expect that soon I'll be quite a bit faster.
But you highlight the issue nicely; bikes are not self-powered, it depends on the human. Even with e-bikes this is true, most of them will only support the rider and have been made not to power the bike all by itself. So how to regulate that? Perhaps a good old speed limit is all that is really needed.
If you want to bike at over 40 km/h then more power to you, but perhaps bike lanes with other, often slower, bikers, aren't the place to it.