My all-time favourite frustration! Traffic lights in Belgium (I have not seen this in other countries) may show a full green light combined with a red arrow. This means that even when you see a full green light you should STOP!!!
I think this is totally unacceptable and (although I don’t have any numbers) am convinced that this setup has contributed to many accidents. What makes it even more frustrating, is the simple solution: show green and red arrows for each direction.