They were followed by Romanians with 2,300 and Germans with 1,800. Slovenes were in fourth place, followed by Austrians, Croatians and others. DARS said it believes the majority of offenders knew that a highway sticker was obligatory but decided to risk it. Slovenia requires anyone driving on a highway to purchase and affix a motorway sticker to their vehicle. Other countries, such as Austria and the Czech Republic, have a similar system while others (like Croatia) collect tolls in tollbooths.