Note by @jeder

back in late 1980s Lublin was rather close to getting its own stadtbahn, called a fast tramway for lack of a better word, which would be using these, hm, very suspiciously metro-shaped trams
not really much info about it but this ryneklubelski.pl/2026/01/gdy-lublin-szykowal-sie-na-tramwaj-rok-1988-i-lubelska-szyna/