Aerial view of M4 motorway

M4 Smart Motorway project

The NSW Government is investing $600 million to build the M4 Smart Motorway project, which will introduce intelligent technology to the M4 Motorway between Pitt Street, Mays Hill and Mulgoa Road, Penrith.

Latest news

NOV 2019

NOV 2019Gradual reinstatement of speed limits

The M4 Smart Motorway work is nearing completion and sections of the motorway will return to the original speed limit. Where construction continues on the Motorway, temporary speed limits will remain in place.

From 5 November 2019, this includes:

  • Eastbound and westbound between Mulgoa Road and the Northern Road
  • Eastbound between Orchard Hills and Roper Road
  • Westbound between Wallgrove Road and The Northern Road
  • Westbound between Burnett Street and the Cumberland Highway

Refer back to this page regularly for future updates as sections of the M4 Smart Motorway return to their original speed limit.

Please see map for details of the speed limit reinstatement (PDF, 108Kb).

Frequently Asked Questions

How will the new M4 Smart Motorway support motorists?

The M4 Smart Motorway will introduce a smarter way of travelling the M4 by using real time information, communication and traffic management tools to provide motorists with a safer, smoother and more reliable journey. More details can be found on the key benifits page.

What does the reinstatement of speed limits mean?

Speed limits are being reinstated to the original speed limit prior to construction on the M4 Smart Motorway. Speed limits will gradually be reinstated between 90 km/h and 110km/h. Where road work continues, an 80km/h speed limit remains in place until work is complete.

A series of 41 overhead gantries are also being installed on the M4 Smart Motorway. From mid-2020, the overhead gantries will provide variable speed limits on the Motorway – providing a more reliable, efficient and safe journey for motorists.

Why aren’t all areas of the motorway returning to a 110km/hr speed limit?

The M4 Motorway has always had speed limits between 90km/hr and 110 km/hr. Where work is continuing on the M4 Smart Motorway, an 80km/hr speed limit will remain in place for the safety of motorists and construction workers.

A series of 41 overhead gantries are being installed on the motorway. Once turned on, the gantries will provide variable speed limits on the motorway.

How will the overhead gantries affect the speed limit?

The overhead gantries will allow speed limits to be adjusted during peak times to help control the follow of traffic – providing motorists with a more reliable, efficient and safe journey. For more information on the gantry installation, view the gantry installation frequently asked questions (PDF, 256Kb).

Interactive map

View ramp closures plus heavy vehicle height and width restrictions. See the interactive map.

View the M4 Smart Motorway map fullscreen.

Project information

The M4 Smart Motorway project, due for completion in 2020 will be delivered in stages, which will help limit disruption along the motorway, and ensure we keep people moving.

From June 2019, Roads and Maritime will be installing 46 overhead gantries along the M4 Motorway between Mays Hills and The Northern Road.

When the project is complete, the gantries will provide motorists with information on current or alternate speed limits and lane status.

Gantry installations will require sections of the M4 Motorway to be closed in both eastbound and westbound directions over five hours between the hours of 11pm and 4am.

For more information about the gantry installation program, follow the link to the Gantry Installation FAQs.

  • Stage 1 - Mamre Road, St Marys to Reservoir Road, Prospect
  • Stage 2 - Reservoir Road, Prospect to Pitt Street, Mays Hill
  • Stage 3 - Mulgoa Road, Penrith to Mamre Road, St Marys

For more information about each stage of work and the upgrades in your area, follow the link to our interactive portal.

The M4 Smart Motorway Project includes a 35 kilometre upgrade along the M4 Motorway from Lapstone to Mays Hill, and will provide a tailored technology solution to create a better travelling experience for motorists, and a more consistent journey.

Smart motorways, also known as managed motorways, use complementary technologies to monitor traffic conditions, manage congestion and respond to incidents in real time. The M4 Smart Motorway will introduce a smarter way of travelling the M4 by using real time information, communication and traffic management tools to provide motorists with a safer, smoother and more reliable journey.

The M4 Smart Motorway will be the first smart motorway for NSW and will bring together intelligent traffic technologies in one place to maximise the performance of the motorway.

More information

For safety reasons, there will no cyclist access on the M4 Motorway between Mamre Road and Reservoir Road from Friday 1 December until project completion in 2020. Please see our cycle detour map.

Register for mobile phone SMS and email updates for the M4 Smart Motorway project, including upcoming ramp closures, M4 motorway closures and project developments.

Western Sydney is Australia’s third largest economy and in its own right would be Australia’s fourth largest city. During the next 20 years the region is expected to grow from two million to three million people, which is why the NSW Government is investing money into significant road infrastructure.

For more information about our projects in your area, see the Projects section.

M4 Smart Motorway map

View or download the M4 Smart Motorway map.

Community information


Contact us

If you have any questions or concerns about the project, please contact us by:

Phone: 1800 989 929


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