Elon Musk has had "promising conversations" with Los Angeles Mayor Eric Garcetti about his plans to build a tunnel network under the city, but acknowledged getting a permit for such a project is harder than creating the technology itself.
The billionaire Tesla CEO has a start-up called The Boring Company with the aim of finding a way to ease traffic. In December 2016, Musk tweeted that LA traffic was driving him "nuts".
So far, pictures have been released showing the digging equipment which Musk's firm will use to make the tunnels. And last month, the Boring Company released images of an electric mass transit system, which could potentially be developed. But so far, there have only been tests of the technology on private land.
Musk has yet to get permission to dig in the city, but according to a tweet on Sunday, conversations with the authorities are going well.
Mayor Garcetti's office is yet to respond to a request for comment when contacted by CNBC.
But Garcetti did say that he was interested in Musk's technology in a recent interview with ABC.
"And like many other cities have, I'd love to see, maybe with the new tunneling technology people like Elon Musk is looking at whether we can have a quick and direct route from LAX to Union Station," Garcetti said.
Musk's idea, as suggested by his tweet, is that the tunnels would not only be suitable for cars, but also bikes and pedestrians too.