Polizia Stradale (Traffic Police) is part of the normal Polizia
(Police), so they usually have a normal POLIZIA plate. But for some years after the end of the second world
war in the province of Trieste there were spacial plates with the words
"Polizia Stradale": the two pictures below, even if their quality is poor, show a plate of this kind for
an autovehicle and for a motorcycle and exactly they both were taken in Trieste.
Unfortunately I don't know other details about these plates: the exact time when they were used or if their use was really limited to the province of Trieste, and I hope to find out something new soon!
The first picture is taken from the issue of April 2001 of "La manovella" and you can find the full photograph I took this plate from in the old photo gallery (picture 18). I want to thank Roberto Grando very much for the second picture.