The I2S project includes the construction of several bridges and level crossings, numerous culverts and a new crossing loop.
Executive General Manager Rail and Transport Steve Butcher said it's an important piece of the Inland Rail project.
"This project will create local jobs and leave a positive legacy in regional NSW. We're proud to continue our partnership with Inland Rail, allowing us to leverage our skills and experience from other sections and draw on our capability in end-to-end rail solutions."