Sign I-30: other danger. Based on reference drawing in Instrukcja o znakach i sygnałach na drogach (English translation: Instruction about traffic signs and signals), made by Ministry of Communication and released in Warsaw in 1975 by Wydawnictwa Komunikacji i Łączności. On January 1st, 1984 the vertical bar has been replaced with exclamation mark.
Own work
Miko101