As a German, I can tell you the problem is that none of these translations are common here, as the whole concept of a speed bump is something entirely ungerman. In fact the first time I've ever seen them was in Mexico, and we were joking that there isn't even a word for it in Germany.
Sure, you could translate it as Bremsschwelle, but I bet your metaphor would confuse most people.
I am originally from north western Germany and they were everywhere, especially in 30km/h zones and play streets. We just called them Huckel and I never thought about an official term. I can not remember seeing any of them in Berlin though. Here they make you break by going left and right instead of up and down.
Interesting, I don't think I have seen them in Bavaria more then in exceptional cases. And even then it's just not something that is present in my head. In other countries though, like Mexico or Thailand, when I think of the roads there, speed bumps are something that I immediately think of.
It might be because they are used differently there. Like they are literally everywhere on each kind of road, so steep that you destroy your car if you ignore them. In a play zone you already have to drive very slow, so they don't bother you, but there you have to actively look for them and slow down. IMO this is because instead of having many bureaucratic traffic rules there, the bumps serve as physical traffic rules. This use case seems to be what OP is referring to in his metaphor.
When was the last time you were talking about speed bumps in Germany?
When creating the site's landing page, I had to investigate where to find speed bumps in Munich. I couldn't remember any, but it turns out there's quite a few in the end. Probably not as popular as in other European countries, though. And there's rarely a signal.
Sure, you could translate it as Bremsschwelle, but I bet your metaphor would confuse most people.