If you ask the LLM to translate something without context, it will translate without context, and the result will quite likely be incorrect. If you provide some context, the result will likely be better. And if you tell the LLM what you are actually trying to say, the result will often be even better.

In this case, the issue was that "speed bump" did not actually mean a speed bump. It was used in a figurative sense, as a cultural idiom. If you tell that to the LLM, it should be able to suggest better ways to express the same idea in other languages.