The job follows on from an earlier £1.5m contract to carry out site preparation works on the North West Cambridge Development.
Skanska will carry out junction improvements and alterations in Madingley Road in Cambridge, to prepare for the next phase of the North West Cambridge Development.
The work begins in this month and is expected to be finished by March 2015.
The North West Cambridge Development will cover 150 hectares and will combine housing, academic and research facilities, a local centre and public amenities.
There will also be parks and other open spaces for people to enjoy.
Skanska managing director Greg Craig said: “The North West Cambridge Development is a fantastic opportunity for Skanska.
“It combines a forward-thinking client with clear objectives, with a location where we are exceptionally well-established, and where we have the right people with the right skills to deliver.
“Skanska has an increasing presence in Cambridge and we are delighted to continue to be working in this vibrant community.”