This crudely printed map of bus communication lines in Poland was printed for the firm PKS (Przedsiębiorstwo Komunikacji Samochodowej) shortly after WWII. Marked are only the routes and the numbers of the buses.
The printing house Orbis was active in Bydgoszcz from 1946 on.
Because the map was printed on cheaper paper, which was avalilable after WWII, the survival rate of such maps is very small. We could not trace any other copies of the map.