Musk's secret plans for an autonomous bus
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Billionaire teases autonomous Tesla mobility service
Tesla founder, Elon Musk, is working on a self-driving vehicle that could replace buses.
The billionaire says the mystery vehicle will reduce traffic in cities, but declined to discuss any more details.
'We have an idea for something which is not exactly a bus but would solve the density problem for inner city situations,' Musk said at a transport conference in Norway.
'Autonomous vehicles are key,' he said of the project, declining to reveal more.
'I don't want to talk too much about it. I have to be careful what I say.'
Tesla has already made waves in the transport industry with smarter more practical electric cars.
Today, Musk said the firm has received almost 400,000 orders for its latest car, the Model 3 sedan.
'We are now almost at 400,000 orders for the model 3,' he told a conference.
He added that the interest in the model had 'surprised even us'.
On April 7, the company said it had received over 325,000 reservations for the model 3.
The billionaire is also looking at a Hyperloop to transport people at 745mph (1,200km/h).
It is essentially a long tube that has had the air removed to create a vacuum.
The tube is suspended off the ground to protect against weather and earthquakes.
Passengers would sit in either individual or group pods, which would then be accelerated with magnets.
apsules carrying six to eight people would depart every 30 seconds, with tickets costing around $20 (£13) each way.
But his latest proposal appears to suggest he is also designing something far less radical – although details were scarce.
'I very much agree with solving the high-density urban transport problem,' Musk said.
'There's a new type of car or vehicle that would be great for that and that'll actually take people to their final destination and not just the bus stop.'
Musk has previously talked about building car tunnels as a way to solve traffic congestion.
'I think this is really a very simple and obvious idea, and I wish more people would do it, which is build more tunnels,' the entrepreneur said in February.
'Tunnels are great, it's just a hole in the ground. It's not that hard, but if you had tunnels in cities, you'd massively alleviate congestion and you could have tunnels of all differently levels.
'You could probably have 30 layers of tunnels and completely fix the congestion problem in high density cities. So I strongly recommend tunnels,' Musk said.