Do you warn opposing traffic with your headlights for "stuff"?

There have been times where "flashing" someone resulted in the flasher getting run down and beaten as a gang initiation. Some wanna be gang members would drive around with no headlights until someone flashed them, then they would turn around, and force the person who flashed off the road and beat them up.

Moral of this story, be careful who you flash and where

If it involves a danger where someone may get hurt, yes I would flash, but if I see a speed trap, nope, if they are dumb enough to speed where they would get pulled over, let them. Police have a leeway, usually 8 MPH over the limit for anything over 40 MPH, so if I'm doing 40 in a 35 zone, I back off if I see a police car, and that is enough to not get pulled over, but those who do 50 in a 35 should get nailed.

 

snopes.com: Flashing Headlights Gang Initiation

 

When I lived in Utah, driving on back roads and two lane county roads, oncoming drivers would often flash their headlights to warn of a county police car doing speed checks

 

HAHA I stand corrected then. I heard that from my neighbor who was a Police Lieutenant with the local city I lived in. I never questioned it! I can actually see it happening though since I grew up in Chicago. Them gangs do some crazy stunts.

OTOH some states will give you a ticket for flashing. The offense is called prohibited use of flashing lights.

 

Most of the time I don't flash my lights for speed traps. I will, depending on the area. I tend to travel winding country roads, so I will flash my lights if there is debri, temp road construction, or someone biking or walking.

 

My grandfather flashed his headlights to let people know about a speed trap, one of the oncoming cars was an unmarked police car. Which turned around and pulled him over. He was asked what he was doing, and told the office that he was warning people about the speed trap. I think the officer laughed and let him off. But that was like ten years ago and I can not remember exactly.

 

In my mostly urban driving, I occasionally encounter three situations
in which I am likely to flash my headlights:

At intersections with opposing or four-way stop signs, when there is
another car that arrived at or nearly at the same time with me, or if I
sense agitation or urgency in the other driver. I will flash and follow
with a waving-through hand gesture to indicate the other car can go
through first. In this case, the flash means "By all means, you go first."

When I see a vehicle ahead apparently wanting to enter or cross my
lane from a cross street, parking space, etc, and I think it unsafe, I
flash multiple times to get the drivers attention (I presume that the
driver is attentive and looking both ways!) to say "Hey! Don't be a
fool, don't do it!" Because there is an implied safety issue, I usually
position my left foot above the brake pedal for instantaneous use
should the other driver proceed. In this case the flashing means "STOP!"

I recognize that in the different situations the flash(ing) means
opposite things... and therein lies the danger of mis-communication.
It is best to vigilant in both situations.

The third situation involves pedestrians or cyclists in the roadway. It
may just be a Ballamer thing, but often on urban neighborhood streets
pedestrians walk in the road, even though there is a sidewalk. Also
those people are dressed entirely in dark clothing. I flash them
whether they are closing or going my way just to say "Hey, I see you!
For next 30 seconds or so, act like you have some sense!"

 

I only flash my lights at someone if their lights are off and it is dark out.

 

I flash for those who do not realize that their lights are not on.
Here in San Diego the police are especially intent on catching people on Crown Point Drive, not an area I frequent much these days. Most folks will flash each other there cause it is a speed trap. They will tag folks for 2-3 mph over.
Additionally I will use it to warn folks that I am there, or the horm depending on which would be most useful in getting attention.
Making yourself visible to others is part of defensive driving. People are too distracted these days.