[Crawford]

Right, I believe Mexico City had the fastest growth of any urban center in recorded history during the 1960's and 1970's, and people were projecting a colossal megacity, multiples bigger than other megacities.

But it seemed the growth hit a wall, and then residents started migrating to cheaper satellite metros a few hours away, like Queretaro and Leon.

And Mexico City has decent transit infrastructure. An extensive Metro system, a pretty good freeway system, and fairly proactive urban planning nowadays. But the city is just waaaay too big, right now. You have a traditional downtown core that might be the size of Milwaukee's core, and then wave after wave of new town centers, until growth stopped at the mountains ringing the Valley of Mexico. The whole city is sinking, and water delivery is a huge issue, as the aquifers are mostly drained.