Such retrofitting should, in particular, target densely populated urban areas as a means of helping Member States to comply with Union air quality legislation.
Le hiarfheistiú den sórt sin, ba cheart díriú ar cheantair uirbeacha dhlúthdhaonra go háirithe mar mhodh chun cuidiú leis na Ballstáit reachtaíocht an Aontais maidir le cáilíocht an aeir a chomhlíonadh.