Wikipedia
Drogowskaz
Drogowskaz is a geometric sans-serif typeface used in public signage in Poland. Originally developed in 1975 by Marek Sigmund for the Ministry of Transportation (to comply with its ordinance from 1960) and put into effect on April 1 of that year, it is currently used in accordance with the Ministry of Infrastructure regulation of July 3, 2003 on all types of road signs in Poland. A free version of the font was developed in 2006 by Emil Wojtacki.
Drogowskaz is distinguished from other sans-serif highway fonts in that it uses the single-story lowercase "a". Leading to type size ratio for this font equals 4:3, thus correct line spacing is, for instance, 12 pt for 9 pt text.