canada has speed limits on bikes too, pedal, motor
(duh), or electric.
i've actually never seen it enforced though. where i live is a perfect candidate for it too... my city is situated on an escarpment, so there are several roads connecting the up with the down. long roads, some twisting around the curvature of the escarpment, but
one of them is part bridge, and is at a constant angle for quite some distance. on top of that, at the bottom of that section, the ground elevation continues to drop for quite a few blocks. if traffic is light enough, you could theoretically pick up a lot of speed. how much, i don't know, but i know i wouldn't drive a car at those speeds down that same stretch of road.