Yes, if by 'miscalculated' you mean 'lied'.
Driverless train technology has existed for decades, and is battle-tested in production.
Yet no place uses driverless trains today.
Figure out why and you can move on to driverless cars.
Autonomous cars won't need guards, and have a capacity of 1 driver per 4 passengers. So the saving per person is 250x higher for autonomous cars than autonomous trains.
That's not even taking into account that the technology for autonomous cars is almost identical to autonomous HGVs - who have huge problems due to the limits of how long they can travel before the driver can rest.
Most rides are 1, maybe 2, passengers.