It's been a while since this changed but I'm posting it here just in case someone was thinking of taking the bus to Barcelona or Zaragoza.

Alsa/Enatcar has changed the departure station of its Barcelona/Zaragoza route from the Estación Sur de Autobuses to the Intercambiador de Avenida de América (subway station: Avenida de América).

The main reason for the change is that the new departure station is better located for those destinations just besides the N-II (the road to Zaragoza and Barcelona).

Thanks!! I am planning on taking this route .