The Southern Suburbs Railway is the biggest element of the New MetroRail project, the biggest public infrastructure project ever undertaken in the Perth metropolitan area (budget of approx. $1.5 b). It involves boring tunnels under the CBD to new underground stations and platforms, adding a railway bridge to the Narrows Bridge, widening the Mt Henry Bridge and running the railway down the centre of the Kwinana Freeway until Thomas Road when it veers south west through the Town of Kwinana and City of Rockingham on its way to Mandurah. Ten stations and new underground platforms at William Street, Perth, will be built as part of the railway. Services are scheduled to begin in 2007. The following is a list of major contracts (greater than $30m) that have been awarded for various Southern Suburbs Railway work:

Package A - Rail spine from Narrows Bridge to Mandurah - RailLink JV
Package B - Cockburn Central, Kwinana and Wellard Stations - Doric Brierty Joint Venture Pty Ltd
Package C - Rockingham and Warnbro Stations - Doric Brierty Joint Venture Pty Ltd
Package D - Canning Bridge, Bull Creek and Murdoch Stations - John Holland Pty Ltd
Package E - Freeway and Bridge works - Leighton Contractors
Package F - City works - Leighton Kumagai