Society's based on some amount of mutual trust. We can't lock everything down and treat every person as a potential criminal. That leads to an inefficient and dystopian country.
That's why you have to pay for insurance (in most places at least) so that you are pre-paying for your liability.
Having recently driven on South Florida freeways, I can vouch for this statement.
It's pretty easy to significantly distrust rail transportation. There are hundreds of rail suicides every year, and each and every time the line shuts down until everything's cleaned up. And of course you could destructively interfere with the train or railway, a rather common sabotage operation during WWII.
When you go through the math on lost productivity due to train delays, you get some interesting conclusions. If a commuter train has 1,000 passengers making an average of $50 per hour who are, a delay is $833 per minute. That means it's more efficient (not going to touch on ethics or legality) to make minimal accommodations for disabled passengers and provide them point-to-point car service, instead.
https://www.bloomberg.com/news/articles/2018-05-22/the-amazi...
'“You only get this chance once. The whole world is watching. I had to," Moreno told investigators, according to the complaint. "People don’t know what’s going on here. Now they will.”'
(Nothing about this story makes sense to me.)
https://www.navytimes.com/news/your-military/2020/04/02/trai...
https://www.azcentral.com/story/news/local/best-reads/2015/1...
But that was a relatively undetermined attack. What if someone welds something directly on to the rails or cuts something out? It may get noticed in tens of minutes, but is that really fast enough?
Similarly it seems like it wouldn't be insanely hard to poison water supplies, doing some damage before it gets shut off or destroy other bits of infrastructure (I hear it has been tried with the electricity grid).
Society is a fairly complex machine and I'm surprised how well it works.
But I am also surprised how well it works. I think people just don't suck as much as one would expect.
The US has a total length of about 300 000km of railway network and that probably counts multi-track connections once. And it doesn’t include subway or anything. So that would be a lot of sensors that need to be placed and maintained. And you’d need to except some failure of sensors, so you cannot just stop if a single sensor goes haywire.
It’s certainly not impossible, but also not trivially done.
While train robberies are now decidedly rare, railroad police still exist today to patrol and protect the right-of-way, particularly in cities where theft, vandalism, and interference remains a real safety hazard. While less glamorous than train robbery, a common problem today is the theft of metal from signals, which disables the signals and creates a possible safety hazard.
"I don't want the ATF to shoot my dog"
<proceeds to dump spent launcher tube they stole from work wherever is convenient>
They make train de-railers specifically to protect work crews in rail yards. Someone who doesn't care about removing it later could just weld a similar shape (a slice of L channel would probably work in a pinch) to a track with some batteries. It should only take about 30sec if you walk up to the track ready to go.
Would have been top news if it weren't for the fact that America was reeling from an explosion of cases in the COVID19 pandemic.