[wirrbel]

> And there are also cases where English has opted for a compound word and German has just invented its own: Ampel vs traffic light, for example.

Ampel is a loanword from latin, "ampulla", it was used for oil lamps hanging from churches and thus kind of made its way into the "Ampel".

The legal texts use "Lichtzeichen" instead of Ampel IIRC.