Warsaw - Some 50 trams in the Polish capital will soon hit the streets with large "sober" signs on the back as part of a national program to fight drunken driving, media reported Friday.

The trams will join a few dozen buses that recently donned the oversized signs, designed in the style of Polish licence plates.

The programme is the brainchild of a Polish priest who was appalled at the number of drunken drivers on Polish roads.

It is part of a broader nationwide programme that promotes a sober lifestyle through billboards, commercials and contests.

Drunken driving remains a problem in Poland, where poor road conditions and aggressive drivers also make it one of the most dangerous European Union countries for drivers.

Poland had the fifth-largest number of fatalities by population, according to EU statistics from 2006, and has one of the worst records of road safety in the 27-member bloc.

Almost 10 per cent of road crashes in Poland involve alcohol, an official report said in 2004. (dpa)