An extension of the M4 remains a NSW Government priority.  In July 2002, the State Government announced it would investigate building an M4 East Motorway that would connect to M4 Motorway at North Strathfield and with Parramatta Road and the City West Link.

In December 2003, three route options, including a favoured option of a 3.6 kilometre tunnel, were released. In June 2004, in response to community comment, this preferred tunnel option was lengthened by almost a kilometre.

In early 2005 the State Government undertook reassessment of delivery of the M4 East in the context of the Government's Metropolitan Strategy  Firstly, the development of any link needs to be considered in light of the expansion of Port Botany and the outcome of the Commission of Inquiry into the port. 

Secondly, any route option needs to be considered in light of residential and business growth in western Sydney.  Finally, any option needs to be considered in light of the NSW Treasury's Working with Government Guidelines.  In 2008, a submission was made to Infrastructure Australia for federal funding to extend the M4 and the project was one of 30 shortlisted for further consideration.

It is anticipated that over the next 15 years Sydney's population will to grow by one million and freight movements are forecast to double. Growth in population and employment places increasing demands on Sydney's road and rail networks.

Supporting this growth, an extension of the M4 would

• Assist in the economic development of Sydney's west by enhancing the strategic road network between the western suburbs, the CBD, Port Botany and Sydney Airport. 
• Provide a high quality alternative route to the heavily used M5 Motorway, M5 East and Eastern Distributor.
• Improve travel times, reliability and safety for local and regional traffic.
• Contribute to urban renewal and population growth by improving the living amenity in Sydney's south and inner west.
• Provide opportunities to improve bus services, both along and across key corridors, in Sydney's inner-west and south.
• Provide for the forecast high growth in freight movements by heavy and commercial vehicles.
• Provide new opportunities on local surface roads in surrounding suburbs for urban improvement, including enhanced cycleways.
• Provide a vital extension of the east-west link into the Sydney Orbital Network. 

Preliminary investigations

The M4 Motorway currently stops at North Strathfield in Sydney's west. Preliminary investigations for three proposed tunnels have been undertaken to assist NSW Government discussions with Infrastructure Australia. These are:

• North Strathfield to the Anzac Bridge.
• North Strathfield to Port Botany and Sydney Airport.
• North Strathfield to Victoria Road east of Gladesville Bridge.

As investigations are still very much preliminary, the proposed options have not yet been discussed with the community. Should the government proceed with planning and development for this project, community consultation would commence.

Community engagement in the planning process is paramount and assists us to identify and develop the preferred project option, including how to mitigate impacts.