I was riding in a taxi when the car in front suddenly flashed its hazard lights two or three times. The foreign student was startled and asked, "Did it break down? Was there an accident?" That's what the student asked, I heard. I'm Korean, so I just smiled. Because that means "thank you." ## Hazard lights are the road's way of saying "thank you" When someone lets them merge in, or yields to them on a narrow road, drivers flash their hazard lights two or three times. You can't hear voices inside a car, so they say thanks with light. It's similar to bowing your head. ## Why does no one tell you this? It isn't a signal set out in the law. It's a habit that drivers have used among themselves for so long that it has become fixed, so it doesn't even appear on the driver's license exam. Koreans naturally pick it up by watching and copying others as they grow into adults, so it never even occurs to them that it needs explaining. That's how it became a greeting that only those in the know understand. ## Here's what to do in these situations - When you're riding in a car: If the car in front flashes two or three times and keeps driving as usual, there's no need to worry. If it's a breakdown, the lights will stay on and the car will pull over to the side of the road. - When you're driving: if someone lets you go ahead, press the hazard light button two or three times and then turn it off. There are a few things to watch out for, too. Leaving the hazard lights on means something is dangerous. Be sure to keep it short.