M4 Smart Motorway Project

The M4 is a 35-kilometre motorway from Concord in Sydney's inner west to Lapstone at the foothills of the Blue Mountains. The M4 Smart Motorway project will see a Smart Motorway system applied to the motorway between Pitt Street, Mays Hill and Russell Street, Lapstone. The project will be delivered in five stages.

Smart Motorways, also known as ‘managed motorways’ use complementary technologies to monitor traffic conditions, manage congestion and respond to incidents in real-time.

Features of the project include:

• traffic sensors located at about 500-metre intervals on the motorway, and on entry and exit ramps, to detect changes in traffic flow in real time
• coordinated, quick-changing entry ramp signals to keep traffic flowing on the motorway and make merging easier and safer
• new lane use management gantries to open and close lanes in response to incidents
• more variable message and speed limit signs – particularly before exit points, and
• new electronic signs on approach roads to warn of traffic conditions and travel times.