Translation:Streetcars are short, but subway trains are long.
Is there a reason the term 'streetcar' is used instead of 'tram' as the main answer. I've lived in numerous countries and never heard of this word.
"Tram" is also accepted. FWIW, I'm (native AmE) familiar with both "streetcar" and (especially from the Philadelphia area) "trolley," which may not get much use these days. "Tram," on the other hand, was never used where I lived in the US ... :-)