Photos have been released of the latest work inside one of the Waterview tunnels.

The giant underground highway which stretches 2.4km beneath New Windsor, Mt Albert and Waterview is nearing completion.

The $1.4 billion roading project will eventually connect the southwestern to the northwestern motorway to form a continuous western ring route.

"Progress underground! Looking more and more like a road tunnel. Auckland start your engines - open early 2017," read the post on the Waterview Connection Twitter account.


The latest photos showed a highway and nearly completed cavernous shell.

The new roadway, which is hoped to ease pressure on the city's central motorway system and the harbour bridge, is due to open next year.