when someone is falling asleep sitting upright. Their head makes a nodding motion whilst they blink to fight back the tiredness.

The few short seconds of excitement when one's turning signal is in time with the car in front of you. Often short lived and followed with predictable dissapointment because not two blinkers are the same.

Someone who is not smart

When a clueless driver leaves their blinker on after the lane change or partial turn has already been completed. Leftover blinker can be dangerous, confusing other drivers who think the car is going to pop in their lane.

To signal after a lane change

When the blink of the indicators on a car matches up with the beat of a song on the radio

When the driver in front of you flips his or her blinker on at the last possible second causing you to slam on the brakes.

Or

When he or she engages the blinker too early and drive past multiple turn options.