HAWTHORNE, Calif. (AP) — Billionaire Elon Musk says he’s almost completed a tunnel under a Los Angeles suburb to test a transportation system that would scoot commuters underground on electric sleds.

Musk tweeted Thursday that, pending regulatory approvals, free rides will be offered to the public in a few months. He also posted an Instagram video of the tunnel.

Last year, the Hawthorne City Council approved an approximately 2-mile (3.2-kilometer) test tunnel from Musk’s SpaceX rocket plant to a point east of Los Angeles International Airport. Musk’s Boring Company is currently seeking approval to tunnel into western Los Angeles.

Musk describes a system in which vehicles would descend via elevators into tunnels and move on electrically powered sleds.

His latest tweet says an operational system would give priority to pods for pedestrians and cyclists.