Elon Musk has a vision of what future transportation could be like when its Boring Company and Tesla work hand in hand. The billionaire entrepreneur has a big plan of boring underground tunnels where autonomous driving vehicles could travel at speeds reaching 150 miles per hour. 

During a flashy event in Hawthorne, California on Wednesday night, Musk showcased a 1.14-mile tunnel that crawls below 120th Street of the city. The tunnel was made by his Boring Company, and it’s intended to serve as a test setup for a much bigger underground transportation plan, according to TechCrunch

Boring Company signage The Boring Company signage is displayed at the tunnel entrance before an unveiling event for The Boring Company Hawthorne test tunnel December 18, 2018 in Hawthorne, California. Musk’s Boring Company is set to bag two high-speed underground tunnel projects connecting Baltimore and Washington, D.C. Photo: Getty Images/Robyn Beck

The test tunnel is equipped with lighting, safety systems, communication and video devices, ventilation and a track for autonomous driving cars. Building the entire setup cost Musk $10 million, and that already includes the digging aspect since the visionary used his Boring Company’s modified machine called Godot.

Musk, along with Boring Company President Steve Davis, maintained that building the tunnels for the proposed underground transport system would be cheaper than building subways because they will be using their own boring machines for it. 

Tesla Model X with retractable wheels A modified Tesla Model X rests on an elevator above the pit and tunnel entrance before an unveiling event for the Boring Company Hawthorne test tunnel in Hawthorne, California. Photo: Getty Images/Robyn Beck

Instead of building just one tunnel from point A to point B, Musk said they are considering stacking several tunnels to make a 3D network that would work like a giant underground highway. Vehicles could then just enter and exit a specific tunnel by entering it through a ramp, spiral or elevator depending on what’s most plausible for a certain location. 

The transportation system that Musk is thinking of building would have a main tunnel where vehicles with retractable tracking wheels as stabilizers could travel. This main tunnel is said to allow travel speeds of up to 150 miles per hour. However, speed is reduced once the vehicle is close to an exit point. 

Boring Tunnel The modified Tesla Model X electric vehicle traveling inside the Boring Co. Hawthorne test tunnel in Hawthorne, California during the unveiling event. Photo: Getty Images/Robyn Beck

Musk said that the beauty of building this type of underground transportation system is that each tunnel could be built throughout the fabric of the city without interrupting or modifying the physical structures above ground. 

Numerous cities have expressed their interest in Musk’s proposed system. However, it would take a long time before a wide-scale adoption of the concept is realized. For now, Musk is showing off the test tunnel by offering a demo ride.

Tesla Tunnel demo ride Elon Musk, co-founder and chief executive officer of Tesla Inc., arrives in a modified Tesla Model X electric vehicle during an unveiling event for the Boring Co. Hawthorne test tunnel. Photo: Getty Images/Robyn Beck

The demo uses a Model X that’s been outfitted with retractable wheels. Musk said the setup could be applied to any autonomous or electric vehicle. But then consumers should take note that the retractable wheels will be offered as an aftermarket product that would retail for somewhere between $200 and $300.