How much does the M6 Stage 1 tunnel in Sydney cost?
The M6 Motorway Stage 1 is the road tunnel project from Arncliffe to Kogarah in southern Sydney that connects the M8 to Kogarah, being delivered for Transport for NSW by the CPB Contractors, UGL and Ghella joint venture (CGU) under a contract awarded in May 2021. It is under construction and the targeted open-to-traffic date remains the end of 2028. A Transport for NSW spokesperson said after the June 2025 state budget that the Stage 1 budget remained 3.1 billion Australian dollars, with final revised costs depending on resolving complex engineering and commercial issues.
Approved budget
AUD 3.1 billion
Approximately $2 billion
Cost basis: 2025
Cost record
How the cost changed
Budgets, contracts and final costs may cover different stages. Each figure keeps its own year and source.
Approved budget
2025AUD 3.1 billion
Approximately $2 billion
caportal.com.auOriginal budget
2018AUD 1.5 billion
Approximately $1.12 billion
caportal.com.auContract value
2021AUD 2.52 billion
Approximately $1.89 billion
caportal.com.auProject record