In Sydney, Australia, the Minister for Roads, Carl Scully, has announced his and the Roads and Traffic Authority’s (RTA) support for a 3.6km twin tunnel to connect the M4 motorway to the City West Link and Parramatta Road at Haberfield.

The tunnel is one of three options being considered for the M4 extension that are described in an overview report designed to draw comments from local communities and businesses.

The other options are a 6.65km twin tunnel, with an additional 1.3km of twin connecting tunnels, or lowering the motorway in a slot. The report shows preference for the short tunnel due to the reduced cost of construction, reflected in cheaper tolls for drivers, and the requirement for less ventilation stacks compared to the longer tunnel option.

Lowering the motorway is thought to be comparable in cost to the short tunnel, but more disruptive to traffic during construction. It is also felt it would not significantly improve the air quality in the region and would require more time before construction could commence as extensive property acquisition and relocation would be needed.

The long tunnel option was suggested by members of the Haberfield community as it would result in a lack of surface works in their area with the tunnel portal being sited further eastwards. The short tunnel option allows for a possible future easterly extension.

Following comments from the local communities, to be received by March, an Environmental Impact Statement will be produced, with additional consultation before the RTA submits a modified proposal for consent.

The scheme aims to enhance the main road network between western Sydney and the Central Business District as well as reducing delays to commercial traffic for the benefit of local and regional businesses. Scully said the M4 extension would provide a crucial link in Sydney’s inner western suburbs.

The M4 East extension will be privately funded. The successful contractor will design, construct, operate and maintain the extension for a 30 year period.



Related Files
Map showing the three options proposed for the M4 extension in Sydney