I think the key point that no one has mentioned is what happens in the case of a crash. It is difficult to assign fault when everyone is under different laws. What happens if you roll a stop sign and get hit by some one who you didn't see? Who is at fault? On a red light, if you stop and then go on a red and a car comes out of nowhere but has a green and hits you, who is at fault?

Same Road, Same Rules.