The same market conditions that led to the multibillion-dollar Sydney Metro blowout are set to impact other NSW government transport projects.

Transport Minister Andrew Constance conceded the forces behind the blowout weren’t contained to the now $15.5 billion rail project during a budget estimates hearing on Wednesday.

Transport Minister Andrew Constance says the same factors that led to the Sydney Metro blowout could also impact other government projects. Credit:Wolter Peeters

Mr Constance also indicated the second stage of the light rail from Moore Park to Kingsford may not be open this month as planned, but he's "pretty confident" it will be operational by May.

He said his government had generated so much work in NSW that it had created a “suppliers market,” which he acknowledged posed concerns for the $55 billion transport infrastructure pipeline.