Signal

If you are driving behind someone, and you feel that they are driving too slow, it is common practice to signal into the left lane and 'pass' this slow person at a rate of higher speed than the 'slow person' is driving.

It is not common practice, however, to signal into the left lane, and precede to drive in the left lane right beside the 'slow person', get the attention of the person you are passing, flip them off, shout angry obscenities until you have their full attention, and then precede to almost crash your car into a ditch because you were concentrating so hard to being angry and not the road.

If this ever happens to you, then please take note that the person to whom you were 'passing' will now content themselves with laughing their ass off at you until you finish passing them.

If you are on a two-lane highway, and construction ahead reads "Warning: Left Lane CLOSED Ahead." And someone tries to pass you but doesn't have enough time and therefore has to slow down and get into the proper lane behind you -- I give you responsibility to smile and wave at the person who was trying to pass you as they slow down to get into the proper lane, thus becoming even more pissed off at you.

Not that I have ever been the "person they are passing" in any of these instances. Nor have I experienced this at least once a week, if not more, since I've been commuting daily. :-)