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1.
When two bus drivers pass each other during their routes, they wave at each other. It happens commonly in both public transit and school bus routes, and is meant to convince the bus drivers that they actually have friends.
Two bus drivers are at opposite ends of an intersection. As they pass, they wave at each other. This is, simple put, a Bus Driver Wave.
by Richard IIIVVVXIVXI April 11, 2010