I wish people would use their turn signals for not only turns, but in advance of lane changes (not just before you may hit them as they move into your lane.) I wonder if they do that last second signaling in case there is a crash to give them some kind of out for their foolish lane changing. However, if you hit someone in the rear of their car, you are almost always the one who is at fault. You did not stay far enough behind the car in front of you.
Stay your distance behind the car in front of you to reduce the chance of hitting the car in front of you. Who cares if the person behind you wants to go faster, you need to be safe.
I think some people turn in front of you or change lanes if they think you can slow down in time to not hit them, instead of waiting when it is safer to turn or change lanes.
Chrissy