Highways England’s project to dual the A30 between Carland Cross and Chiverton Cross has been in the pipeline for several years.
It is now the only remaining stretch of single carriageway on the A30 between Camborne and the M5 at Exeter.
Development consent has been given to upgrade the road from a single to dual carriageway which includes construction of a 12.5 km new off line section and a new grade separated junctions at Chiverton and Carland Cross, and Chybucca.
The majority of the existing A30 will be retained as a local route.
Highways England is in the process of appointing a contractor to deliver the £290m project, which is hoped to move forward with preliminary works in the Spring and be opened by 2023.
The Planning Inspectorate’s Chief Executive, Sarah Richards said: “This is the 80th nationally significant infrastructure project to have been examined and decided within the timescales laid down in the Planning Act 2008.”