Fast Children Need Not Apply - Reverse Frogger

Frogger is this video game, now old, that has the player try to move the Frog across a wide variety of places, all of them with traffic.  For example, crossing a river by jumping on logs that are moving by, or crossing a road and not being hit by cars.

It is the "crossing the road" version of the game that came to mind when I saw the road sign shown below.

 

So, here is the question.

Why do the slow kids play in the road?
Does that even make sense?

Where do the fast kids Play?

Why have I never seen a Fast Kids Playing sign?