You're asking some relevant questions but the problem is that we have NO breakdown on the nature of those "human errors." To assume that they were all as a result of rail employee's actions is as reckless as it is to assume that none of them were. Without a breakdown on all of the causes by type neither one of us can answer that question. That being said, your observation is worthy of note.Lets say you're correct that the leading cause is human error. Sounds like we need better training, perhaps better hours. I don't know how many hours these people work or how many days in a row. However when these people were fighting a few months back for a few days of sick leave each year I have to assume its a brutal schedule. I work in a warehouse. Ten hour days six days a week is not unheard of and at some point you become a danger to yourself and others.
If the second is rail failure this is a multibillion dollar industry. If you have to inspect every single inch of road no less than once a month, more often for heavily traveled routes get people on that. This also sounds like a damn good reason to build more rail just to cut back on wear and tear and allow other routes to be taken while this line gets basic maintence.
The third might be unavoidable since I have no idea what goes into train maintence. It sounds fixable. Maybe there needs to be a top to bottom inspection and tune up every 'x'. I won't pretend to know enough about trains to know how often this would need to be. But I rotate my tires, get oil changes, sometimes a tune up for no real reason to keep my car going.
I accept that shit happens. We can minimize how often it happens. The fact that this happens SO often that it usually doesn't even make the news is pretty terrifying.
Rail failure includes a whole category of sub-failures. These failures can also include failures caused by third parties intentional or accidental. I know that the major operators stay on top of their rail maintenance for obvious reasons.
I return to "where it makes sense." The majority of the nations goods travel by rail. Crippling the industry with overarching regulations will only drive those goods to be moved by trucks, a far more dangerous form of transport not to mention far less 'green.'