Truckers spend a lot of time on the road, and they often develop ways to communicate with each other. Radios can help, but they also use their lights to signal, as it’s quick and easy.

One of the most common signals is when a truck needs to merge over into another lane, but there is a vehicle behind it. For instance, maybe one semitruck is passing another on the interstate. When that driver gets around the slower truck, he or she needs to move back into the right-hand lane. Due to the length of the trailer, though, the driver may have trouble knowing when they have gone far enough to change lanes again.

What the rear truck driver will often do is just to flash their lights one time. That just means that the trailer has cleared the cab and the lane is empty. The driver in front may have issues with blind spots and visibility, so this signal is appreciated.

The issue is that not everyone understands the signals that truck drivers use, and there is no official guide. For instance, say you’re hoping to pass a truck at night. You worry that the driver can’t see you, so you flash your lights once to let them know you’re there. Then you start passing. Unfortunately, the driver thinks you mean there is room to change lanes and he or she merges right into your car.

All it takes is one minor miscommunication to cause a serious accident. If you get injured in a crash with a truck, be sure you know if you have a right to compensation.