(7) The car directly in front of you has a flashing right tail light
but a steady left tail light. This means
(a) one of the tail lights is broken; you should blow your horn
to call the problem to the driver's attention.
(b) the driver is signaling a right turn.
(c) the driver is signaling a left turn.
(d) the driver is from out of town.
The correct answer is (d). Tail lights are used in some foreign
countries to signal turns.
-- Pittsburgh Driver's Test