Whether they are drunk, lost, wireless or just clueless, the danger signs are similar: sloppy control of speed, direction or lane position; failure to attend to such basic items as turning the lights on at night or dimming them or signalling a turn or a lane change; or overlooking things as obvious as a light that has turned red or green, stop signs, well-marked dips or speed limits. These folks often don't move at the same speed as the rest of traffic, and they tend to be slow to react when traffic starts moving or begins to slow, or it's their turn to go when turning left. They are also very slow to recognize and react to changes ahead that will affect them, such as a car stopped to parallel park, and then tend to do a poor job of dealing with the problem. In the last week, for example, I have seen two drivers on cellphones who got caught behind stopped traffic. One saw what was going on too late, screeched to a stop and then honked, but he never realized that he'd have been able to change lanes and pass with no problem if he'd been paying attention. Another in the same situation with the phone to his left ear sort of tried to look left before changing lanes but couldn't really see because of the phone. He changed lanes anyway, slowing as he did so, and forced the overtaking driver (with me behind him) to mash on his brakes. But I watched the situation developing long before the errant driver realized he had a problem, so I was sitting back waiting for it.