In Germany I've often seen "Spielplatz" with long slope course for Kinder, playng with such sleigh , and one with light metal body around it which has also a lever for strong brake .

They can enjoy and at the same time ,experience "the fast speed" since the childhood in such away.
I think German infants naturally obtain the feeling for the high speed and get to know the danger (or limit ?) about "the speed".

By the way , does this "machine" have a brake system?