You are driving along a deserted stretch of highway. It is getting dark. In the distance, a car is approaching without its headlights on. You flash your own headlights to remind the other driver to turn their lights on. The other car’s lights come on. Tires squeal as the car turns around and follows you. You hear the engine rev as they get right on your bumper. Shots ring out…
This is the scenario feared by many thanks to a long perpetuated hoax involving the use of headlights for a gang initiation activity. But while this frightening scenario has been exposed as a hoax, there are many scenarios where people do use their headlights to communicate. How and for what purposes headlights are used for communication vary by location and have evolved over time.
To flash one’s headlights means to briefly toggle the headlights between low beams and high beams, usually to signal to an oncoming vehicle in the opposite lane. This use of headlights for communication became more widespread during the 1970s, when automobile headlight controls were relocated on newer vehicle models from a switch you press with your foot on the floor to controls you manipulate with your hand on the steering column. The controls on the steering column were also wired to work so you could toggle between high beams and low beams even when the headlights were not initially on.
There are a variety of messages which can be communicated by flashing headlights at an approaching vehicle. One message is, as the hoax described above explains, to remind a driver to turn their own headlights on when it is getting dark. Another reminder which is often conveyed is a reminder to the other driver to switch to low beams in the face of oncoming traffic so as not to blind those drivers (including you). Drivers also flash their lights to warn oncoming traffic of an accident they recently passed. And, as has been in the news recently, drivers flash their headlights to warn other drivers when they are approaching a speed trap.
It is this message, warning other drivers of police officers laying in wait to give tickets at points in the highway where the speed is drastically reduced, that has been the subject of controversy and court cases. On the 23rd of February 2014, U.S. District Court Judge Henry E. Autrey issued a permanent injunction against the town of Ellisville, Missouri, to forbid law enforcement officers from detaining, seizing, citing, or prosecuting individuals who are perceived by police as communicating with other drivers by flashing their headlights. This has been perceived as a big victory for defenders of freedom of speech, and it is not the last time or place where this issue has been addressed. Less than two months later, a judge in the state of Oregon ruled that a sheriff deputy could not detain and cite an individual for using his headlights to warn a UPS driver of the deputy’s presence. The defendant in this case appeared to refer to the Missouri decision when asked about his defense. The American Civil Liberties Union was involved in both cases.
It is not the moral of this story to evade law enforcement or to disobey traffic laws. But consider yourself informed that multiple judges have independently determined that in the United States, you have a constitutional right to freedom of speech which includes communicating with your vehicle’s headlights.