The Impregilo-Salini joint venture has been awarded the $340 million construction contract for the four kilometre elevated skytrain, including a new bridge over Windsor Road at Rouse Hill.
Work is now underway on Australia's biggest public transport project.
Two of three major contracts have been awarded for the North West Rail Link.
The skytrain contract will deliver a 270 metre cable-stayed bridge over Windsor Road at Rouse Hill.
