We rented a car from Hertz in Germany last July, 2013. We made arrangements through AAA here several months in advance and got what we thought was a good deal. We were very surprised to receive a registered letter with a traffic ticket this week (February, 2014) from Vienna, Austria. With difficulty, we translated it from German and found out we had driven on a toll road, A23, without the required vignette. That is a sticker that is required to be displayed on the windshield. The letter said we owed a fine of 550 euros. We contacted the honorary Austrian consulate in Minneapolis, who did not completely understand the letter either. He said he would look into it, but advised us to pay it. It seemed to offer us an appeal, if we acted within two weeks. It took us a week to figure that out!
We drove through four countries, Germany, Austria, the Czech Republic, and Poland, without stopping at the borders. We paid tolls at toll booths in Austria to go through the mountain tunnels, and several other places. We thought this was the common way to pay tolls.
WARNING! Stop at the border, at a gas station, and inquire about tolls! We had no idea that the road we were on was a toll road, or that these vignettes were for sale and were required. We are law abiding citizens, who would have purchased this if advised to by either AAA or Hertz. We think it negligent of these companies to not advise about this. The web site on Austrian tolls, says they have been in effect since 2002. We did not know enough to look this up specifically before this. We did not see this in the books by Rick Steves, as we read several of his books before our trip.
We were also stopped by the Czech police for a similar reason. There we were directed to a petrol station, like an American oasis, to purchase a toll sticker. Neither the police or the girl working at the gas station knew any English, and we do not know any Czech. The brochure the Czech police held and pointed out, said there was a 5000 crown fine. The sticker cost us 440 crowns for monthly access. I think there was a shorter term one, but we bought what we could.