An aligned but less radical and more implementable approach was later proposed and named as Distributed Air-Ground Traffic Management (DAG-TM),[12] keeping ATC still with a significant role, but allowing more freedom in en-route airspace.[13] Besides, other relevant aspects in a wider context have been studied in the Mediterranean Free Flight project[14][15](MFF) which had, as one of the main conclusions, that self-separation would be overall beneficial, but it should have to be limited to low- or medium-density airspace.[16]