Why is this even an issue? Demonstrators have occasionally blocked entire downtown sections of Mexico for days and hold rallies on the zocalo. The 1968 massacre in Mexico for the Olympics is a scandal to this day that makes the PRI quiver in their boots. One bout of violence was enough.
Where I live the indigena regularly block Mex 200 and rant as best they can their grievances against the local, state and federal government.
And guess what? The police do not injure or kill them with shotgun bean bags or rubber bullets. They let them vent their frustration, then go home.
Some years ago protesters who got screwed out of their land for the creation of Mex 37-D commandeered the toll booths and collected donations. I made the mistake of holding my fist up in a sign of solidarity and the net thing I knew I was being slapped on the back and the amiable crowd was pouring high octane moonshine Mescal down my throat out of bota bags. I had to pull over onto the shoulder and let the effects of the buzz wear off.
Yeah, HOW were they "screwed" you ask? Toll road owners offered them 1/2 down CASH for their land, a promise to let them "cross" the autopista to the other-side to access the rest of their property, then NEVER BUILT the overpass access points and FORGOT to pay them (for many years) the OTHER HALF of the payment out of the collection of tolls.
So as Steve Martin says "Well Excuuuuuuuuuuse Me!" if protesters cause inconvenience to travel plans, including, especially, my own.
The ambulance? Did it have it's red lights flashing when it pulled up to the barricade? Many times an ambulance is used for non-critical transport, or simply to get from one place to another. The indigenas at Michoacan's X villages cleared the highway one time and let a Cruz Roja ambulance pass through and these folks barely speak Spanish. The Mexicanos waiting in their cars were similarly concerned to let the emergency vehicle pass quickly.
The only thing THIRD WORLD about Mexico, are some of its visitors...