I am all about the latest innovation out of Hawaii! Let a newer bus merge in front of you and you may see a digital sign on the back of the bus light up. What does it say? “Mahalo” which is Hawaiian for “Thank you.” Then it flashes the famous “shaka” hand signal.

Apparently, bus drivers have been offering a shaka to generous motorists for generations. But until recently, they were limited to the analog version of the gesture: rolling down the window and sticking their hand outside. As buses get bigger, it is getting harder to see the driver’s hand from the back of the bus. When Honolulu designed a fleet of new cutting-edge buses, someone had a brilliant bit of inspiration. A government official explained:

“The drivers of the new buses have a little switch they can hit that flashes the shaka on the back sign. In the old buses, you have to lean out the window and stick your arm out into traffic to say thanks. This just makes it a lot easier.”

Michelle Kennedy, director of marketing an communications for Oahu Transit Services

This Honolulu transit system, simply called “TheBus,” was upgraded with some new fuel-efficient vehicles in 2013. How often would a bus driver actually need to merge? Pretty often. Honolulu is the ninth worst city for traffic congestion in the U.S.A.

When TomTom did its yearly traffic ranking, New York City got the worst rating of the U.S. It was followed by Washington D.C., San Francisco, and Boston. While hand gestures aren’t unheard of in these other cities, I don’t imagine you see the shaka often. But maybe all of our commutes would be better if you did.