If it were anyone else, the notion of digging hundreds of miles of tunnels to create a new subterranean transportation network under congested cities would seem like pure science fiction.
But the dreamer behind this vision is Elon Musk, the billionaire innovator who has already shown with his Tesla electric cars and SpaceX rockets that he thinks big and doesn't wait for others to transform fantasy into reality.
Once again, Musk is aiming to shake up an arcane industry not used to outside-the-box thinking and yet potentially ripe for disruption: the underground world of tunneling.
More from USA Today:
No, that wasn't a driverless car driving around Washington
CVS Health store customers down as competition heats up, discounts drop
Analysis: Toyota-Mazda plant deal shows how rivals can be buddies
He could use tunneling to achieve his moonshot goal of clearing up Los Angeles traffic. It also could be employed to build a "hyperloop" system — a passenger capsule that magnetically levitates inside a tube to achieve high speeds — that would run 226 miles from New York to Washington, D.C. Travel time: 29 minutes.
Musk hopes to dramatically speed up digging by inventing new tunnel-boring-machine technology that could slash billions from a major project.
Tunneling is big business. In the U.S. and Canada alone, there are about 60 major tunnel projects in the planning or design phase totaling more than 1.8 million feet, according to the Underground Construction Association of the Society for Mining, Metallurgy and Exploration.