The WestConnex M4 tunnels are set to open as part of a 33km mostly underground motorway scheme in Sydney, New South Wales, Australia.

The M4 tunnels are expected to reduce travel times for Western Sydney drivers on Parramatta Road.

New South Wales Premier Gladys Berejiklian said that the new M4 tunnels will bypass 22 sets of traffic lights from Homebush to Haberfield and cut up to 20 minutes off a trip from Parramatta to the Sydney central business district (CBD).

Berejiklian said: “We are now just days away from drivers benefiting from the first underground section of WestConnex.

“This is yet another major project which will allow people to spend less time in traffic and more time doing what they want.”

Australian Population, Cities and Urban Infrastructure Minister Alan Tudge said that the M4 tunnels are the first of four tunnel pieces in WestConnex.

He said: “This gamechanging project will help bust Sydney’s congestion, cutting travel times and return local streets to locals.”

The $3.8bn, 5.5km twin tunnels will have three lanes in each direction and extend the widened M4 from Homebush to Haberfield.

The M4 tunnels are expected to reduce the traffic volume on Parramatta Road by 53% by 2021.

NSW Minister for Roads Andrew Constance said that 67,000 trips are expected to be made through the new M4 tunnels a day within two years.

Constance said: “WestConnex will take up to 10,000 trucks a day off Parramatta Road, which is welcome news for anyone who sits in bumper to bumper traffic on that notoriously congested corridor.

“I would like to thank communities for their patience throughout construction over the past three years.”

The WestConnex project also includes the new M5, the M4-M5 Link and the Rozelle Interchange, connecting Sydney’s west and south-west through more than 30km of motorway.