Sao Paulo is very famous for its transit issues. Thousand of cars cause dozens of kilometers of traffic jam every single day in town. Most of the drivers listen radio for hours, while they are stuck on the streets.
This video-advertisement [Portuguese] was published by a Brazilian company called Brastemp in São Paulo. They transmitted the same message on 11 different radio stations at the same time, asking for people to smile for the driver of the car on their side. It quickly became a contagious trend and everybody started to smiling to everyone. That was an admirable and creative way of input something good into the tough routine of many Paulistanos. Congratulations!