Inside the never-before-seen operation linking M4, M8 tunnels

A new tunnel linking the M4 and M8 motorways could save motorists up to 40 minutes. The Daily Telegraph was taken for a never-before-seen tour of the new tunnel. Watch the video here.

AS Sydney sleeps, more than 200 experts have embarked on an immense challenge never seen before in Australia.

Over a series of 40 nights, two live tunnels carrying thousands of motorists every day will begin “talking” to each other, in one of the final stages of work to connect the M4 and M8 motorways.

The work will integrate more than 1,000 cameras, 2,000 km of cables, 3,964 LED lights, almost 1,700 PA systems, speed limit messaging signs, and more than 4,000 emergency lights.

It is one of the last steps in connecting the M4 at Haberfield with the M8 at St Peters, creating a record 22km long mega-tunnel to slash travel times by up to 40 minutes, Transurban says.

The tunnels are almost connected physically but now need to link up via innovative technology so drivers can remain safe, traffic can flow and incidents can be addressed quickly.

The wall that will be knocked down to open up a section of WestConnex that will then be linked to the M8, nudging the WestConnex closer to completion. Picture: Richard Dobson

Eventually, a section of wall known as the “secret door” will be knocked down to connect the M4-M5 link to the M8.

Traffic and safety in the WestConnex tunnels will be managed from the country’s largest Motorway Control Centre, which features a video wall of 60 panels.

The “secret door” will soon be knocked down. Picture: Richard Dobson

The tunnels’ nerve centre will co-ordinate critical incidents, maintenance and network-wide traffic monitoring.

“WestConnex is Australia’s biggest and most ambitious road infrastructure project – and this sort of integration work has never been done in the nation’s history,” WestConnex boss Andrew Head said.

“With up to four lanes in each direction, the 7.5km M4 and M8 link will be future-proofed with world class traffic management systems, which will be designed to talk to the next phase of electric, connected and automated vehicles.”

The M4 and M8 will be temporarily closed for a series of 40 nights between now and when the tunnel is due to open next year.

Group Executive for WestConnex and Transurban Andrew Head and Asset Operations Support Telaine Grapsas in the WestConnex Transurban Motorway Control Room. Picture: Richard Dobson

”We are disrupting the network a little, but we’re looking at the greater good we are creating with that new tunnel,” Ms Grapsas said.

“Our closures are planned well in advance and to create minimal disruption.”

The first night of works was completed last Monday, with another closure slated for next week.

The new tunnel – which was previously known as the M4-M5 link will be officially referred to as extensions of the M4 and M8 motorways.

“Once complete, the tunnels will significantly improve connections between west andsouthwest Sydney, reducing travel times into the city for Western Sydney residents,” Roads Minister Natalie Ward said.