Appointed contractor Skanska is now expected to start main works at the end of the summer on the £143m contract awarded at the start of the year.
The scheme is designed to increase capacity for local economic expansion, reduce congestion and pave the way for the planned HS2 Birmingham Interchange station in Solihull.
The project, which is expected to open to traffic in 2023, involves building a 1.5 mile new dual carriageway link between the Clock Interchange and a new junction on the M42 north of the Solihull Road
There will also be improvements made to the existing junction 6