As the result of this completion the existing A473 from Gwaun Meisgyn to Treforest route was downgraded to the B4595 meaning that "Power Station hill" became part of the A473 Pontypridd to Bridgend route which also meant that the A473 now starts at the A470 junction at Upper Boat rather than Treforest. It also meant that the A4058 in Treforest and Glyn Taff became part of the B4595 Treforest to Talbot Green route meaning that the A4058 will start from the junction at the A470 in Pontypridd and follows its usual route to Treorchy.
As a result of this change, the existing A473 from Gwaun Meisgyn to Treforest was downgraded to the B4595, meaning "Power Station hill" became part of the A473 Pontypridd to Bridgend route. This also meant that the A473 now begins at the A470 junction at Upper Boat instead of Treforest. Additionally, the A4058 in Treforest and Glyn Taff was incorporated into the B4595 Treforest to Talbot Green route, so the A4058 would start from the junction with the A470 in Pontypridd and follow its usual path to Treorchy.