Also, flashing lights can be used for a variety of other things. I had someone flash their brights at me recently, and several deer was in the road about 1/2 mile further on.
It used to be that flashing brights was used to let someone know they hadn't turn off their brights, or to let someone in the left lane know you wished to pass.
Because so many people get their panties in a wad because someone honked or flashed their brights...the state of Washington has made it ILLEGAL to do those things.
You go to other countries, and these things are considered part of driving, and a courtesy.
So putting your hand out the window and making a motion up & down could also be considered "Warning" about a police officer. Sorry...though the law may support AdamZ, I have to be honest...going after a driver for doing that is kind of petty...you should have more important things to worry about. What about CB radio where truck drivers will warn about cops?
Seriously, giving a ticket for this is just plain stupid, IMHO
