While the Class 66s began their service in 1998, No. 66004s unique livery and service reflect a modern preoccupation with promoting environmental awareness.The HS2 owned locomotive is part of an active drive to promote the environmental benefits of delivering construction materials by rail instead of road, which inspired the name 'The Green Progressor'. The intention is that for every locomotive HS2 uses to transport aggregates and construction materials, up to 76 lorries are removed from the UK's roads and motorway network. 'The Green Progressor' is both innovative and a benefit of tradition; in returning focus to our beloved railways we boost efficiency and reduce emissions.