This has been a pet peeve of mine for a very long time! I think part of the reason for it is because there is not a lot of traffic coming out of Bristol Road, generally, so people actually are unaware that it's a street, and that the intersection, as you say, it 4-way. I also think it's because Willow Ave and Bristol Road don't line up exactly, like most intersections would. For this reason, I think many people truly don't realize that there could be cars coming from Bristol onto Willow. I am giving them the benefit of the doubt here, but trust me, I'm not so polite when I'm driving. I try to jump out ahead of cars which are turning, and honk if I have to!