Too many people nowadays seem to have forgotten how to use their indicators. All too often I follow people who slow down and slow down and slow down to the point of basically being parked in traffic, and only once they've caused the obstruction do they use their indicators. If at all.
It would be so much more helpful (for those of us who aren't telepathic) for you people to actually indicate your intentions ahead of time. That way, we have a chance of keeping the traffic flowing by going around you.
Instead we're presented with what is essentially a parked car. Have they broken down? Had a medical emergency? Which side do I go around? Left or right?
On more than one occasion I've had people park in traffic like this, and as I've gone to go around them, they've nearly turned into me. The scenario is very typical in Utah where I live, where nobody knows how to drive, much less understands where they are or where they're going. They'll amble along in the left lane, then realising they need to turn right, they'll slow down to a complete stop (with no indicators) waiting for a gap in the traffic in the right lane. As everyone behind them is being forced to go into the right lane to go around them, they're stuck until they do eventually turn right across the traffic and cause an accident.
I think part of the problem in Utah at least is that they mistakenly call indicators "blinkers". That tells me all I need to know. These people don't believe those pretty orange lights are there to indicate their intentions, they believe they're there to blink on and off.