Businessman Elon Musk has demonstrated part of a planned high-speed, underground transportation system in California. Musk is best known for founding electric carmaker Tesla and aerospace company SpaceX. But two years ago, he announced on Twitter plans to launch a new company. His tweet said the business, later formed as the Boring Company, would seek to ease traffic in the city where he lives, Los Angeles. “Traffic is driving me nuts,” Musk wrote. So he promised to build a tunnel-making machine and to “just start digging.” Musk says the Boring Company’s aim is to make a series of tunnels in Los Angeles and other cities. The company is developing equipment to dig faster and make the process more cost effective. Elevators would lower passengers and vehicles into the tunnels. Musk said the vehicles could travel at speeds up to 241 kilometers an hour. He wants to use electric, self-driving vehicles to move people around the city.