Soon after the news had emerged that ERTMS was installed, but not operational on the High Speed Line from Ourense to Santiago de Compostela, ADIF confirmed that ERTMS had not been in operation due to an incompatibility problem between the infrastructure and the rolling stock. Adif says that “There was an incompatibility between the trains and ERTMS lines: it took ages to recognize each other and therefore it could not be made to work.”
According to ADIF, when executing tests and communication problems arise, the system can not be homologated. “And so ASFA is being used” says Adif. ASFA reliable, though less sophisticated and safe, but it is being used on 90% of the Spanish railway infrastructure.