The Heads of the Valleys Highways Improvements Scheme, Section5 and 6 extended from Hirwaun in the west to Dowlais Top in the east, passing to the north of Merthyr Tydfil. The length of the scheme was 17.7km. The scheme was predominately an on-line improvement of the existing A465 trunk road. Six junctions were provided within the scheme, all of which were grade separated. The junctions included Hirwaun, Croesbychan, Baverstock, A470, Prince Charles Hospital and Dowlais.