MISSOURI (NEXSTAR) – If you’ve ever had someone flash their headlights, or their “brights” at you while you’re driving, you might wonder why they did that, or if that was even legal to do.

Flashing the headlights of a vehicle can be done for a slew of reasons. Some drivers may be trying to give a warning to other drivers about a potential speed trap ahead, or they might try to tell another driver that their brights are on unnecessarily. Other reasons include indicating that they intend to pass another driver on the road. Some drivers may simply flash their brights to let other drivers know that they can go first at an intersection.

Regardless of the reason, is it legal for drivers to flash their brights at another vehicle in the state?

In many states, flashing your headlights to warn other drivers about a speed trap was illegal. For drivers in Missouri, that changed back in 2014. A federal court in St. Louis ruled that drivers are allowed to flash their lights to warn other motorists of nearby police and speed traps. The court ruled that it’s a first amendment right.

The American Civil Liberties Union (ACLU) has stepped in numerous times across the country, representing individuals concerning this subject, as KSN in Joplin explains. The particular ruling for Missouri stemmed from a 2013 case in Ellisville when a driver received a citation for flashing his headlights “to notify motorists of a radar set up ahead.”

“The police cannot retaliate against drivers who have done nothing wrong and are simply exercising their right to communicate with other drivers,” said Jeffrey A. Mittman, executive director of the ACLU of Missouri.

In other words, you are completely within your right to flash your brights in Missouri.