With all the advances in cars and drones it seems like trains should already be traveling without a person in the cockpit. To me it seems surprising that there is not even a discussion about this here in Germany where the was a train crash recently where a train dispatcher was playing a game on his phone and caused the crash because he was not paying attention. https://en.wikipedia.org/wiki/Bad_Aibling_rail_accidentWhat are the main issues with a technology solutions? Are any startups working on this?