Well, I thought I'd catch you up on some of the aspects of life here. I go to school on the bus every day and while these pictures don't illustrate well, it can be an adventure. Frequently busses are very crowded during rush periods and people just keep squishing in. The other day I ended up hanging on in the stairwell with one hand on my pack and the other gripping the post. The door was open and the street was rushing by while the driver weaved in and out of traffic and made sudden stops.
This is about as swank as a city bus in DF can get. I ride these on Insurhentes to school which is one of the main arteries in town. Busses of this quality are rare though and many are much older and beat up. You'll notice this one even has TV screens which I guess are functioning at night.
The other busses are private peseros which are smaller, green and travel on smaller streets and follow routes that baffle the mind, but afford some efficiency at times because they circumvent the main roads, but no one is safe from the rush hour crawl.