Road blocks. The feds robbed land to use for a toll road between Lazaro Cardenas and Patzcuaro. Periodically the violated land owners would kick the toll road employees out of the toll booth and collect donations from motorists.
The donations were absolutely voluntary but almost no one I have seen ahead of me had decided not to donate. Non donors were ignored as they passed through the booth. There were dozens of sympathizers holding signs and distributing refreshments to everyone.
I made a mistake
I held my left hand out the window with clenched fist
A sign of camaraderie. My friend, my neighbor Eduardo lost thirty acres of mango orchard and was never paid a cent.
Next thing I knew I was parked on the shoulder, beyond the toll booth swilling bootleg tequila and musing acidly about how Eduardo had lost his land (no access to maintain the trees). I knew better than to try and drive. So I spent three hours in a "nap" then drove the rest of the way home with an overexcited jack hammer at work inside my skull.
I would smile a concerned smile at student protesters. Accept printed literature and then while maintaining the smile say "NO COMPRENDO". In such a circumstance I do not admit I speak Spanish. You will be left alone.
The indigenous at the X villages between Manzanillo and home on the coast route sometimes protest and block traffic. Nowadays village elders are much more strict about alcohol and drunkeness, but many young people still brandish rifles (.22 and they are unloaded) They rant at Spanish speaking car occupants, but when they see my gringo face with a concerned smile, most of the time they clear a path and insist I leave.
No big deal. But just image what gossip fodder this makes when you get home! The authorities will reopen the highway in an hour or two.
The percentage chances of you encountering a protest are small indeed.
