Also, they use it on freeways when there is a traffic ahead. By keeping the hazard blinker on, drivers can see it from the distance and thus more time to reduce their speed. This communication method is more commonly used among relatively younger Japanese drivers and I think this is such a clever way to communicate. Drivers in Hawaii rarely honk at other drivers. In Japan, however, it's not unusual.
Japanese drivers honk at other people in a way to express their frustration to others.
Because honking can startle people due to its unpleasant sound, it can elicit anxiety and anger in other drivers. But, it can be misundertood and even be taken as offensively by people who don't hold the same meaning. My second observation describes another miscommunication between drivers. From my understanding, smiling to other driver in such a situation means obviously asking for a little courtesy. When he nodded, I thought we had an understanding that he would let me merge into his lane.