Drivers cite laziness for not using signals:

I hate these people! I absolutely hate it when someone pulls some stunt right in front of me without using their turn signals! Of course, if I were to hit them, it would be my fault because I'm behind them.

"A new national survey reveals that 57% of American drivers admit they don't use their turn signal when changing lanes, but what is most interesting are the excuses drivers gave. According to Response Insurance, a national car insurer, 42% of those drivers say they don't have enough time, 23% admit they are just plain 'lazy,' 17% don't signal because when they do, they forget to turn it off, 12% admit they are changing lanes too frequently to bother, 11% say it is not important, 8% say they don't signal because other drivers don't, and 7% say forgoing the signal 'adds excitement to driving.' The survey was conducted by Response Insurance."

The other thing I hate is when people try to squeeze you out when you do use your signal! Let me make this clear: My turn signal is a statement, not a question. I've already decided that there is enough room for me to change lanes. If you cut me off, it will be your fault.