Musk suggests the first tunnel will be located near the SpaceX headquarters, five minutes from LAX.

Tesla Motors and SpaceX CEO Elon Musk already claims to be making progress with his tunnelling project."Exciting progress on the tunnel front," he wrote in a Twitter post. "Plan to start digging in a month or so."

The idea was first proposed just five weeks ago when Musk lamented the Los Angeles traffic and claimed he would "build a tunnel boring machine and just start digging." He joked that it would be called "The Boring Company."

It is unclear if the tunnelling project has already established an official route that will be used for public infrastructure, or if it is merely entering an equipment testing phase on private property.

When asked where the first tunnel will be located, Musk replied "Starting across from my desk at SpaceX. Crenshaw and the 105 Freeway, which is 5 mins from LAX."

The SpaceX headquarters is located adjacent to the Hawthorne Muni Airport, with its parking garage located across the street on the east side of Crenshaw Blvd. It is highly unlikely that the company has received the necessary permits and resolved all red tape to begin work on any extensive tunneling project. A Quartz report points out that Trump's initial idea to build a tunneling company was made public just hours after three employees were hit by a driving while they crossed Crenshaw, suggesting a possible motivation for SpaceX to start with a tunnel -- perhaps just a walkway -- to connect its headquarters to the adjacent employee parking area.

If the tweet refers to a tunnel that starts at the SpaceX building and ends at the 105 Freeway, such a route could allow employees to reach the nearest Los Angeles Metro rail station without stepping foot on surface roads.

Musk has not yet clarified any specific details of the proposed tunnel route.