Back from Mexico City - some observations....
There are no stop signs in Mexico City. Sounds odd, but I think there's a point: it forces drivers to be much more cautious around intersections without traffic lights, because they know that if anyone blows through, chances are, there will be a collision.
I love the "street life" of "CDMX" (Spanish for "Ciudad de Mexico" aka Mexico City) which is varied and vibrant. At any given moment you can encounter an entire restaurant set up on a street corner (grills, stoves, tables and chairs), or someone selling a refrigerator out of the back of a pickup truck. Lots of shoe shine/repair people, and, of course, musicians, beggars, artists, you name it, it's happening on the streets and sidewalks of CDMX.
It is unbelievably clean: people are out each day sweeping and washing the sidewalks, and caring for the trees in front of their homes and businesses. And there is a lot of green in the city (despite all the pollution.)
There is security everything, police and private. Every store, apartment house, public space seems to have a heavily padded (but not armed) security officer with a walkie talkie out front.
Food is very inexpensive - "street tacos" are a buck and delicious.