Train control is not super complicated, it has been deployed in various forms in Europe for decades. Rail infrastructure providers offer turn-key solutions base

Train control is not super complicated, it has been deployed in various forms in Europe for decades. Rail infrastructure providers offer turn-key solutions based on common standards like ETCS. It is expensive due to a lot of hardware that needs to be deployed, but that's it. Even countries like China with their CTCS use it on modern rail lines. One of the problems is that you can't really use GPS for location awareness because it can be down without notice and is not available in tunnels. Maybe that restriction will be lifted one day. But there are proven solutions, the US is just too stingy to buy them.