Frequently asked questions

Smart Motorways, also known as managed motorways, use real-time information, communication and traffic control systems incorporated into and alongside the road to improve traffic flow.

Smart motorway technologies are being used on Melbourne's M1 motorway and introduced in southern Queensland on several roads including the Ipswich Motorway. Some individual elements of the technology are already in place on Sydney roads including the M1, M2, M5 and M7 Motorways.

Yes, studies have reported a significant reduction in motorway incidents and improved traffic flow. On Melbourne's M1 Motorway reports have shown:

• Travel times have been reduced by up to 42 percent
• Crash rates have decreased by 30 percent
• Vehicle emissions have been reduced by 11 percent.

The project aims to lessen congestion and keep traffic moving across the M4 Motorway network. Less stop-start traffic reduces fuel consumption and reduces CO₂ emissions.

The concept design and environmental assessment phase of the M4 Smart Motorway project was jointly funded by the NSW and Australian governments.

The project is being developed as part of the National Smart Managed Motorways Programme, which targets major economic routes and aims to improve freight, business and commuter connections with key locations, including employment centres and major transport centres like the airport.

The NSW Government has allocated $395 million towards the M4 Smart Motorway project along with $75 million from Roads and Maritime Services’ consolidated fund.

For more information visit the Department of Infrastructure and Regional Development website.

The first stage of work commenced in October 2017.

We anticipate the complete managed motorway system will be operational by 2020.

Ramp meters, or ramp signals, on entry ramps are quick change traffic lights that manage the flow of vehicles entering the motorway. They make merging safer and easier and reduce the risk of drivers having to brake suddenly.

Ramp metering will operate during peak periods or in heavy traffic, for example, as a result of an incident. A sign at the beginning of the entry ramp will tell you if ramp metering is in operation.

Traffic sensors along the motorway, and on entry and exit ramps, will continually monitor traffic conditions. The sensors will detect changes in traffic conditions early and switch the ramp meters on before the motorway reaches capacity.

The timing of the ramp meters change with the demand at each entry ramp and on the motorway itself. The timing is coordinated with other entry ramp meters along the motorway.

No, entry ramp meters will operate in peak periods or in heavy traffic, for example, as a result of an incident.

The system may operate all, some or none of the ramp meters, depending on traffic conditions. Due to the dynamic nature of the system, it will continuously monitor traffic conditions and operate automatically at any time in response to changing traffic conditions.

No, it is anticipated that for most journeys, the travel time saved on the motorway would be greater than any minimal delay that may be experienced at an entry ramp.

We are modifying entry and exit ramps to ensure there is enough space to manage traffic volumes without impacting traffic already on the motorway or on approach roads.

No, the motorway will still be called M4 Motorway.

No, there will be no permanent change to speed limits on the M4 Motorway. Variable speed limits will be in operation if there is heavy traffic, an incident or other adverse conditions.

There will be no toll introduced to this section of the M4 as part of this project. However, the section of the M4 east of Church Street will be tolled as part of the WestConnex project.