The public transportation is a dream here compared to that of my former home in California where buses were inadequate and infrequent..
Combi's (vans that have seating for 10-12) run every five minutes her in Morelia. The cost went up this year and is now 6 pesos. There are numerous long routes passing through the city intersecting with other routes.
It is my bet that a person can go from any place in Morelia and its outter villages to any other with never needing to use more than two combis, to get from anywhere to anywhere.
Most likely there is a combi nearby that will take you near most of the popular destinations. They are labelled by color and a route number. Within a couple blocks of my home I can catch the Gris 1 that runs a circuit around the pereférico, or the Roja 1 that travels Pedregal to Madero then along Acueducto. Negra 1 passes close by and runs through several colonias to around Mercado San Juan, Santuario de Guadalupe, through Chapultepec colonias to Las Americas Plaza and into colonia Ocolusen near Club Campestre. There are several other combi routes nearby as well, most of which I have never ridden.
Coral 2A has a base very near my home in colonia Lago III about 1km from Estadio Morelos and the central that leaves out of Av Quinceo, down Av Poliducto to Av Michoacán and into the Centro, then runs parallel with Madero past the large terminal area at San Francisco and turns to go past Mercado Independencia up to run alongside the rio chico and onto Blvd. Garcia León for a distance, then turns again to pass the old stadium and runs a section of Bucarelli until it turns again to head into Mercado Abastos, then nearby to its base at the other end of its run. It takes about a full hour to run its full route.
Then there are the larger municipal buses also that have routes through the city and to neighboring towns and villages. Just about anywhere you could possibly be in this area the buses and combis pass nearby regularly typically from 5am to 9pm depending on the route. I count about 43 combi routes that operate inside the city of Morelia.
"There is no route out of the maze. The maze shifts as you move through it because it is alive. "
— Philip K. Dick (VALIS)