WestConnex Stages 1, 2 & 3

Sydney, NSW


The Project

Proposed $17 billion, 33km continuous motorway which will link Sydney’s west and south-west with the CBD, Sydney Airport and Port Botany precincts. The entire project involves 19km of tunnels and 14km of surface roads, and will provide a three to four lane motorway in each direction. WestConnex comprises three stages of construction:

  • Stage 1 - M4 widening and extension from Parramatta to Haberfield;
  • Stage 2 - M5 East duplication from Beverly Hills to St Peters; and
  • Stage 3 - M4 South from Haberfield to St Peters.

Our Services

MIEngineers conducted an options study and cost engineering of Section 1a, Section 1b, Section 2, Section 3, St Peters Interchange, Baylink, Gateway and Stage 2 of the local road upgrade works. Our estimating work included:

  • First principles estimates of all related road, bridge and tunnel infrastructure;
  • tender assessments of D&C contractor bids;
  • determining maintenance outturn costs and the implementation of project cost savings; and
  • the delivery of potential sub-stages within the design.

MIEngineers was also tasked with conducting options studies on the Roadheader and Tunnel Boring Machine methods of excavation to determine the most efficient and cost-effective technique for the tunnel works.

MIEngineers was also involved in the following WestConnex related projects:

WestConnex Enabling Works – Airport East Precinct

The Airport East Precinct project comprises the development of a road underpass of the existing Port Botany rail line to allow the removal of the existing level crossing adjacent to Sydney Airport. The project involves extremely complex limitations of flight paths, significant utilities, live rail, heavy traffic conditions and limited space.

MIEngineers prepared a detailed construction method statement for inclusion in the Environmental Assessment, and provided engineering advice to ensure the feasibility of the concept design.

O’Riordan Street Upgrade

MIEngineers provided expert constructability and utilities relocation advice to RMS at the strategic options phase of the project. MIEngineers reviewed the options for the upgrade of O’Riordan St to suit potential WestConnex alignments and Sydney Airport access upgrades. MIEngineer’s advice was significant in the determination of a preferred option for development. MIEngineers also provided strategic cost estimates for the proposed options to allow cost to be considered as part of the value management process.