Originally Posted by jpdx
Nomination for strangest, and most dangerous, use of turn signals: The Mexican states of Puebla and Oaxaca. A slow moving car will signal that the road ahead is clear for passing by using the left turn signal. Obvious complication: The same sign is also used to say, "keep off, I'll make a left turn."
I've seen that in many other countries, and "sometimes" I find it very effective.
Especially on busy single lane highways.