I'm driving down a two lane road, one of the main roads out of town, and some guy stops to make a left turn. It's rush hour and there's no way he's going to make that turn. I look behind me and there's already 20 cars stopped, all the way back to the last intersection. This one guy has halted all traffic on the outbound lane of the town. If he had gone up two blocks, there would have been a left turn lane, but he didn't.
Don't be that guy...
If there's no left turn lane, no center lane or no intersection with a left turn arrow, try not to turn left. Some times you can't avoid it, but if driving around a block will avoid halting 20-30 cars for minutes at a time, drive around the dern block!