The above (maybe) works in the
US. In
Mexico you vigorously wave your hand (and newspaper, if you have one) to stop a
pesero.
Since the pesero driver is a very
private entrepreneur he might well elect not to pick you up, maybe because he is in hurry, or because you look like a
bad guy.
Government buses, on the other hand, stop no matter what.
What is difficult is getting them to move.