Billionaire Elon Musk is changing the plan for his tunneling venture.

Instead of creating first underground transport system to help cars circumnavigate traffic congestion, Musk is shifting his tunneling venture to be more like a mass transit system.

Musk announced the change over his personal Twitter account Friday.

Adjusting The Boring Company plan: all tunnels & Hyperloop will prioritize pedestrians & cyclists over cars

The tunnels Musk is digging via his infrastructure business, The Boring Company, will house pods on tracks that zoom underground for pedestrians and bicyclists to travel in.

Those not driving should be allowed to go first as a matter of fairness, Musk says.

Will still transport cars, but only after all personalized mass transit needs are met. It's a matter of courtesy & fairness. If someone can't afford a car, they should go first.

The Boring Company system will be different from a city subway system, says Musk, because the pods would go to more more locations and each pod will be smaller than a subway car.

Boring Co urban loop system would have 1000's of small stations the size of a single parking space that take you very close to your destination & blend seamlessly into the fabric of a city, rather than a small number of big stations like a subway

Musk posted an animation of what the system will look like (embedded below).

Better video coming soon, but it would look a bit like this:

The pods would be able to move up to 150 miles per hour, Musk says. One Twitter user asked whether it would be fair to call the pods buses. In a way, he says. Very fast buses.

I guess you could say it's a 150 mph, underground, autonomous, electric bus that automatically switches between tunnels and lifts. So, yes, a bus.

Musk, who is already the boss of both electric car maker Tesla and aeronautics company SpaceX, says he tried to get others interested in building tunnels for years but failed and eventually took on the challenge himself.

"It's not because of some epiphany that I had one day driving on the 405," he says, referring to a famously congested highway in Los Angeles, where the tunnels are being built. "That's how it gets translated somehow. I was talking about tunnels for years and years, for probably five years or four years at least.

"Whenever I would give a talk and people would ask me about what opportunities do you see in the world, I would say, 'Tunnels. Can someone please build tunnels?'" Musk explained at the South by Southwest tech conference in Austin, Texas on Sunday.