Barcelona -bus/stop numbering question.

I am using google maps to plan a rout from La Sagrada Familia to Placa d'Espanya. It offers several combinations using either the Metro (which I assume is the subway) or a direct route using the bus with the number 50. My question/confusion is that if I click on the bus stop that is suggested, google pulls up a list of buses from that station such as B24 or N1 but no 50. This seems confusing. Do you just trust that a bus with a number 50 will come by?

There is most certainly a bus 50 that runs a route that includes Plaza Espana, the Gran Via across the Eixample and then up to the Segrada Familja zone.

It may be that the stop is on a one way street as is the case in a few areas on the route. It is also possible that google maps is just pulling up busses from that station in the minutes around your search. Any N bus runs at night and the letter busses transit zones and the simple number busses transit zones with many stops. There is a kind of system to the letters and numbers, but it is sometimes unclear.

http://www.tmb.cat/en/linia-de-bus/-/bus/50

Bus map for whole city.

http://www.tmb.cat/ca/c/document_library/get_file?uuid=5e6af5e2-7677-4ce8-85bb-8e63f2b086f1&groupId=10168

Thank you for the reply and information. I'll look into it. I was wondering if there was a method to all the letters/numbers. Thanks again.