I am not a native speaker of German and I’ve been learning the language for some months.
Recently, I read some texts about cars and I noticed the word Geschwindigkeit, which means speed in English. I noticed also that this word is used in the speedometer of the cars.
I wonder why the translation for speed is Geschwindigkeit (from the adjective geschwind + ig + keit) and not another German word that is closer or more related like Schnelligkeit (from the adjective schnell + ig + keit).
Is there a specific reason why Geschwindigkeit is used instead of Schnelligkeit to indicate the speed of a vehicle? Is Schnelligkeit uncommon or wrong to say speed?