M4 Smart Motorway - Stage 2 and Stage 3

Project Location

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Project Description

Seymour Whyte is delivering Stage 2 and Stage 3 of the M4 Smart Motorway, between Parramatta and St Marys in western Sydney.

The motorway is New South Wales' first smart motorway, introducing intelligent technology to Sydney’s roads that will help manage traffic congestion and prevent crashes for the 100,000 daily motorists that use the motorway.

Both stages of the project involved:

  • Motorway ramp realignment, extension and widening
  • Installation of ramp meters and ramp control signs 
  • Installation of overhead gantries, variable message signs, traffic sensors, CCTV, and speed and motorway lane use signs to adjust speed limits, and open and close lanes as needed
  • Installation of maintenance bays, vehicle detection loops, emergency phones and upgrades to power and communications infrastructure.

The ITS solution included:

  • 80,000 km of optic fibre cable
  • 650 vehicle detection loops
  • 264 integrated speed and lane use signs
  • 59 roadside cabinet upgrades
  • 40 CCTV poles and cameras for road monitoring
  • 30 variable speed limit signs
  • 12 ramp control signs to regulate the flow of traffic
  • 3 variable message signs providing real-time information and communication to motorists, and
  • 19 motorway emergency telephones to support incident response.

All major construction on the M4 Smart Motorway has been completed. A phased trial of equipment and technology started in September 2020.

Stage 2 and Stage 3 form part of the overall 36km stretch of the M4 Smart Motorway, which has been divided into several packages and is expected to cost a total of $600 million. The project is funded by the NSW government.


May 2018 to 2020

Transport for New South Wales (TfNSW)

Contract value
AU$250-300 million