The cause was due to an engineer texting and ignoring a red signal.
Which has nothing to do with wether it is a freight railroad or not.
Freight and passenger vehicles share the interstate all the time. Rail can do the same. The problem today with freight and passenger rail is that the private railroads abandonded many lines making them single track where they use to be double and triple tracked. The congestion is all self induced. By the way many of these lines are now re-building their single tracks into double tracks again.
You need to brush up on what PTC is and what it does...
Because we cannot police civil servant behavior while driving, until such systems are implemented our freight and passenger systems cannot share the same lines safely.
You are advocating public takeover of privately owned systems? Sounds awfully Venezuelan...
Another big differential are the speed limits of the two systems. Freight systems are typically much slower than passenger lines, and high-speed systems use entirely different track designs and configurations altogether.
Again, we are a long way away from sharing systems on the same lines.