Traffic Sign - What does it mean?

Yield, and proceed one by one. Kind of like a four way stop sign in California. In theory, you take turns.

Many Zihua intersections have no STOP signs - only one saying "Ceda el paso - Uno y Uno".

I get the gist, but what does it mean in practice? The sign appears, for example, at the intersection of Vicente Guerrero and Catalina Gonzalez. Experience tells me that traffic on Gonzalez seems to have the right of way: vehicles on Guerrero trying to go through that intersection tend to yield. (Except for taxis, which always drive halfway into any intersection as a sort of intimidation tactic, hoping they'll "win".)

Just curious. When in Rome.....

This is a recent and IMHO extremely stupid imitation of the traffic management in Morelia. It means "stop and let the other guy go one at a time". Since almost no one here has ever taken a driving class or even a drivers test (no test to get a license) too many folks haven't a clue what traffic culture is or even how to use a turn signal. We have for years become accustomed to certain downtown streets being non-stop through streets while others are stop at every intersection, but this stupid imitation of Morelia throws a monkey wrench into the works.

NEVER trust anyone else to obey the traffic signs or to even use their turn signal correctly. EXPECT people to make turns from the wrong lanes with no warning. EXPECT people to run stop signs and traffic lights. And of course expect that these stupid signs will only confuse folks who already don't know how to drive. And above all, if someone hits you whether walking or driving expect them to leave from the scene of the accident post-haste. If you are a foreigner in an accident no matter whose fault you think it is, I guarantee you everyone else will hold you responsible and be expecting you to cough up the big bucks.

The closest thing to driving lessons most folks here ever get is the bumper cars at the fairs.