One of the annoying things about the auto industry - other than the fact that "Back to the Future" clearly proved that we should have had flying cars at affordable prices by the year 2015, a target that they have now missed - is that they insist on not building automated vehicles quickly enough. Instead of spending our commutes or shopping trips chatting with friends, getting a nap or catching up on some work, we have to keep two hands on the wheel and obey an incredibly long list of rules as we pay attention solely to driving. We can converse a little or listen to music, sure, but generally speaking, we're stuck with the repetitive task of maneuvering a heavy machine among a bunch of people of questionable competency, all doing likewise.
Is this a good way to spend our time? Of course not! Thus, it's no wonder that some of us don't do it perfectly. After all, we are only human, and if we get annoyed and go a little faster, that's very understandable. We have places to be! Why shouldn't we cathartically let out our rage at the buffoons who get in our way? Why should we waste our hard-earned money on having two brake lights in working order when one is surely enough to signal our intentions?
Why not indeed - and the answer is not just that it's a lot safer, it's also because the alternatives will get us pulled over. It's wiser to do everything right, and get pulled over for a mistake instead of a purposeful infraction. That way, when you are pulled over anyway, at least you'll know why!