That was at the last town which was a bit larger. I was still inside the town and thought I had to keep the low speed till I encountered the end of town sign as

That was at the last town which was a bit larger. I was still inside the town and thought I had to keep the low speed till I encountered the end of town sign as the biergarten guy told me. Additionally I thought the signage less than optimal: rather small signs behind bushes and so on. Once or twice I saw the speed cameras before the sign. So that's why I felt it's their own fault.