Translation:In the traffic playground, children learn traffic rules.
How do you call this thing https://goo.gl/maps/qYyekp3ceLR2 , then? There are intersections and traffic signs placed there as on real roads.
Please understand that if we want to teach this concept, we have to translate it somehow. The other option, not impossible, is to remove this from the course. It might indeed happen.
We had this discussion on a translators group a while back and concluded that there's not one term for it in English like there is in Czech. That park in Southampton calls theirs a "cycling training track" so it's probably meant for kids learning to pass their cycling proficiency tests. A wider one for cars could be a driving training track / training area.
I think "traffic playground" is a bit confusing because the word traffic usually means "provoz" rather than "doprava".
The fact that the concept does not exist, or the term for it does not exist, in the English-speaking world -- and I certainly don't know if that is true -- does not mean we can't learn it. I've never heard it before, but I understood the meaning the minute I saw the English sentence. We are, as learners sometimes point out when we try to explain English concepts, here primarily to learn Czech, after all. :-]