With all this talk about self-driving cars, it&#x27;s really depressing (and tragic!) to see so little progress on self-driving trains (Positive Train Control).<p>Think about how much easier self-driving trains are to implement!  There&#x27;s already no expectation that a train can swerve to avoid the unexpected obstacle, there&#x27;s already digital switching to make sure the train goes in the right direction and instruct the engineer to stop, and the retrofit problem is much easier, since all locomotives are part of a fleet (as opposed to privately-owned cars).