Definition 1 of 1
Before the advent of reliable indicators "hand signals" were used by vehicle users to indicate they were turning. To get a driver's license it was mandatory to become familiar with them. As reliable indicators and AC cars and buses became more popular this died a natural death.
However it is still common to see painted on the "backside" of the new generation AC buses the sign " AC vehicle no hand signal"
Added 2011-12-19 by Cyanide