M4 Smart Motorway project


Project overview

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, Parramatta and Mulgoa Road, Penrith.

Latest news

Apr 2021 – Gantry installations

The M4 Motorway will be closed for one night from 11pm, Monday 19 April to 4am Tuesday 20 April to install four final gantries. The motorway will be closed between The Northern Road and Mamre Road, with detours in place. See the April 2021 gantry install notification (PDF, 431Kb) for more details.

Dec 2020 – Sydney's first smart motorway given the green light

The state's first smart motorway has been permanently switched on after a trial in which the intelligent technology provided motorists with a smoother and more reliable journey.

View the media release for more information.


Interactive portal

To learn more about this project, view our interactive portal for more information.

Project information


The M4 Motorway is a 50km long motorway that opened in Sydney in the 1960's. It stretches from the suburb of Concord in the inner west to Lapstone in the Blue Mountains.

Over the years, the M4 Motorway has become a popular route which connects a number of different industrial and commercial areas including Homebush, Silverwater, Parramatta and Penrith in the west.

During peak times, the motorway carries anywhere from 3,200 to 7,100 vehicles in either direction. Around 75% of trips completed are private vehicles but motorway usage also includes freight transport and bus services.

Due to increased development and traffic volumes across Western Sydney, the M4 Motorway often operates at capacity resulting in significant congestion.

This traffic congestion was found to reduce safety, increase delays and travel times for drivers while also increasing vehicle emissions.

In 2015, the NSW Government began preparing to implement smart motorway technology which could improve the overall reliability, safety and incident management on the M4 Motorway.

Aerial view of the completed interchange with The Northern Road (then Bringelly Road) in 1971. Scanned from Main Road Journal.
Looking west on the Great Western Highway at Prospect, showing the former left turn lanes to the westbound freeway.

The M4 Smart Motorway (M4SM)

The M4SM project is an upgrade to the motorway along the main section of the M4 Motorway from Parramatta to Penrith. It involves installing new structures and technology which will work together to create a smoother, safer and more consistent travelling experience for motorists.

The M4 Smart Motorway will be the first smart motorway in NSW. Smart Motorways, also known as Managed Motorways, uses complementary technology to monitor traffic conditions, manage congestion and respond to incidents in real time.

Test your knowledge of the new features on the M4 Smart Motorway. Work hard to beat your high score by learning how the new motorway works.

View the M4 Smart Motorway Quiz.


Ramp signals - keeping you moving

A more consistent drive

Traffic conditions are monitored in real time and entry ramps signals, known as ramp meters, manage the number of vehicles coming onto the motorway with a quick change traffic light system during peak times. These tools ensure a smoother, uninterrupted driving experience.

Safer, smoother and more reliable journeys.

Safer journeys

Crash rates on Smart Motorways are reduced by up to 30%.

Travel time savings

Reduced travel times

Traffic keeps moving so overall journey times are reduced.

Real time information - helping you.

Current information about traffic conditions

Drivers will be able to see real time information on message boards to help them make informed decisions about their route before and during their trip on the motorway.

Improved incident management.

Better incident management

If there is a incident variable message signs will indicate the safest speed and which lanes to are usable. These variable signs help improve access for safety crew and emergency vehicles.

Reduction in vehicle emissions

Reduced vehicle emissions

When traffic flow is improved and there is less stop-start driving, vehicles have better fuel consumption and produce fewer emissions.

Completion schedule

Construction work in the M4 Motorway was undertaken across three main stages and began in 2017.

The first stage of work was Mamre Road, St Marys to Reservoir Road, Prospect

Key features of Stage 1

  • Widening the M4 Motorway from three to four lanes in each direction between Roper Road and the M7 Motorway

  • Building new maintenance bays along the M4 Motorway between Mamre Road and Reservoir Road

  • Installing new emergency phones which will be connected to the incident management system

  • Building three new noise walls and extending one existing noise wall

  • Upgrading three interchanges at Reservoir Road, Wallgrove Road and Roper Road, including the installation of ramp meters and ramp control signs, as well as widening and realigning entry ramps

  • Upgrading communications and power infrastructure to improve reliability of the corridor and support the rollout of additional electronic messaging, video surveillance cameras, vehicle detection devices and ramp metering

  • Installing vehicle detection loops and CCTV cameras at each interchange to better manage traffic flow onto and along the motorway.

The second stage was Reservoir Road, Prospect to Pitt Street, Parramatta.

Key features of Stage 2

  • Installation of maintenance bays, vehicle detection loops, emergency phones and upgrades to power and communications infrastructure

  • Installation of variable message signs, traffic sensors, CCTV, and speed and lane use signs between Pitt Street and Cumberland Highway

  • Realignment, extension and widening of ramps at Burnett Street, Coleman Street and Cumberland Highway, and installation of ramp meters and ramp control signs.

The third stage of work was Mulgoa Road, Penrith to Mamre Road, St Marys.

Key features of Stage 3

  • Installation of maintenance bays, vehicle detection loops, emergency phones and upgrades to power and communications infrastructure

  • Realignment, extension and widening of ramps at Mamre Road interchange

  • Installation of ramp meters and ramp control signs at Kent Street and Mamre Road.

As of May 2020, all major construction on the M4 Smart Motorway has been completed. A phased trial of equipment and technology will take place before a full opening in late 2020.

Community information


To assist with the flow of traffic on the motorway, ramp meters have been installed on entry ramps for the M4 Motorway. This installation has meant that traffic flows consistently onto the motorway reducing the gaps for cyclists to cross over.

For the safety of cyclists they should continue to use the alternative route that has been in place since 2017 for travel between Penrith and Parramatta, as their permanent route to the M4. For more information about where this route is located please see the map.

Media releases

Contact us

For further information about this project, please contact:

Phone: 1800 989 929

Email: m4smartmwy@transport.nsw.gov.au