The complex £60m-plus junction upgrade will see the firm build two free-flowing connections between the A47 and the A11 as well as additional lanes and pedestrian crossings.
A new half-mile link road, with a 40mph limit, will also be built providing direct access to the junction from Cantley Lane South and Norwich Road (B1172).
An earlier decision on the DCO for Thickthorn junction was postponed in September following the Queen’s death.
Around 3,000 new residential dwellings are potentially planned near the junction, along with commercial business units
The project is one of six major improvements and almost half a billion pounds of investment National Highways is making to the 115-mile section of the A47 between Peterborough and Great Yarmouth.
The first of these – a £17m upgrade to Guyhirn junction in Cambridgeshire – officially opened in May.
Traffic modelling data shows the section of the A47 between Thickthorn junction and the Ipswich Road junction is used by over 60,000 vehicles each day – making it one of the busiest stretches of the road in Norfolk.