1. Left-lane interstate tailgaters (you're already going 80) who force you over and then immediately get off at the next exit.
2. Serial lane changers who never signal their intentions, as though it were a sign of weakness, but simply drift right or left whenever the need strikes them.
3. People who refuse to use their headlights on dark, foggy, rainy or snowy days because they can see just fine without them.
And all of them have Massachusetts license plates, except for the few from Rhode Island, who might be drinking or texting as well.
I've done informal tests (counting how many cars out of ten have their lights on) of these morons, and it appears to be about ten to fifteen percent of all drivers.