Elon Musk's pipe dream of being able to bypass road traffic by travelling in subterranean tunnels is now closer to reality than ever before after he was given permission to dig a two-mile long test tube in California.

The Tesla and SpaceX owner's next venture goes underground with his Boring Company's vision of allowing car owners to whizz through tunnels by driving onto high-speed 'electric sleds'. So far it has already carved out a working tunnel underneath private company property. Now, the city council of Hawthorne has given approval for an extension to stretch out beyond into city territory.

The longer test tunnel, dug 44 feet down, will run from the SpaceX headquarters two miles out into the Hawthorne surroundings below public roads and utilities – but the council has confirmed it will not go beneath any private or commercial residences.

Representatives of the Boring Company have sought to reassure that people living in the area will not be disturbed by the large machine digging away below, claiming "they won't even know we're there".

It also wanted to comfort concerned residents worried about the possibility of the ground collapsing by stating the company would measure soil daily. If it shifts more than half an inch in either direction, they will stop work immediately until a solution is found.

While the approval is a major breakthrough in Musk's quest for more efficient methods of transportation, the tunnel may not even be used in the future. The dig is mostly a test to see how viable the Boring Company's vision is, and the city can request to have the created tunnel filled in with concrete or soil after work has been completed.

Elon Musk revealed the Boring Company's vision back at the beginning of 2017 as he promised to "solve the problem of soul-destroying traffic". He claimed that "unlike flying cars, tunnels are weatherproof, out of sight and won't fall on your head. A large network of road tunnels many levels deep would fix congestion in any city, no matter how large it grew (just keep adding levels)".

Testing The Boring Company car elevator

A post shared by Elon Musk (@elonmusk) on

Musk shared a video of the alternative transportation concept in action with a Tesla (naturally) being lowered into the tunnel on an elevator, showing the ambitious project is rapidly taking shape.