The nearly completed M4 tunnels are estimated to help reroute up to 10,000 heavy vehicles daily from Parramatta road the NSW Government has announced.

Joining Homebush to Haberfield, the 5.5 kilometre section of WestConnex will reportedly allow drivers from Western Sydney to bypass a significant section of congested Parramatta Road and connect direct onto the City West Link.

This would include a diversion for truck operators from 52 sets of traffic lights.

According to Premier Gladys Berejikilian, who this week toured the nearly-completed M4 tunnels, 67,000 trips are anticipated every day during the first two years of the first stage of WestConnex.

“We’ve seen first-hand that the tunnelling and road pavement for the long promised project has been completed. We are on the home straight for the new M4 tunnels, with fit-out of the tunnels now underway.”

On the same tour of the new site, Minister for Roads Andrew Constance thanked the communities of the Inner West for their patience while the work was undertaken.

“We appreciate the delivery of city-shaping infrastructure takes time, and it isn’t easy on those who live nearby. I look forward to the new M4 tunnels opening soon and taking thousands of vehicles off local roads,” he said.

Berejiklian said WestConnex will link Sydney’s west and southwest with the city, airport and port precinct in more than 30 kilometres of continuous motorway.

"Once all of WestConnex is complete in 2023, drivers will be able to get from Penrith to the Anzac Bridge without having to stop at a single traffic light and travel times from Parramatta to Sydney Airport will fall by up to 40 minutes," she said.

"Traffic volumes on sections of Parramatta Road will also be reduced by more than 50 per cent.”