Im currently in Colombia...spend several months a yr here..and most cities,except Bogota have excellent bus service...all run by private companies. Cheap and clean. Never have to wait more than a few minutes for a bus.
Contrast that to Broward-Miami Dade.
Check out this Econtalk episode w/ Mike Munger on what happened when Chile socialized the bus system:
http://www.econtalk.org/archives/2008/07/munger_on_the_p.html