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."
All over Mexico, ancient custom required that after twilight, cars would flash their lights when (a) coming up on curves, of which Mexico has a Switzerland-sized allowance, and (b) as a signal to cars behind that no cars were approaching and it was semi-safe to pass.
The canyons and deep valleys of Mexico are strewn with battered and burnt metal of the vehicles of drivers who thought they were receiving signal (b) when the driver ahead was signalling (a).
Imagine speeding up to pass, and finding that you're accelerating off of the edge of a precipice into the vast and dark unknown below (as Mexico may not have gotten around the guard rails, and the occasional white-washed boulder along the verge provides little protection....
On dark nights, if one listens closely, one can hear the ghostly panicked cries of mistaken drivers.