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> Why is that?

What exactly?

A conductor always just gets a movement order. They are not able to assess whether the track is clear, that's the reason why the signalling system exists in the first place. How they get that movement order doesn't necessarily tell what the security steps were to back it.

Of course an attentive conductor can notice and mention there something being weird ("Doesn't the other train normally arrive first?"), but that's a rare lucky occasion, nothing to be relied on. And they just need to swallow the answer ("No, you go first today...") anyway.

> and conductor just wouldn't move unless green

The conductor won't ever move unless they get a movement authority, which most of the time is a green signal.

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so in this case, couldnt conductor just say - make it green, not my problem, staying still until then
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Theoretically yes, but in practice if you tell your boss to screw off multiple times a year because they don't want to spend the money to fix the base problem, you will be replaced or fired.

In some industries that is how they keep costs low while pretending they are being safe. They have alarms or procedures that say something is bad or wrong, but fixing some problems costs more money than it saves so they want them to be ignored, and managers will get angry and admonish you or eventually fire you if you keep following procedure and stopping to check problems. So eventually they build a team of people essentially trained to ignore problems. Which is why many oil pipelines still use ancient and unreliable leak detectors, they know those systems are unreliable and the operators will get alarm fatigue from the 200 false alarms, and that way they also ignore when a real problem happens, and worse case for the company they scapegoat the operator. They don't care that 2,000 gallons of oil leaked into the wilderness and poisoned the land if it would cost 2,000+ gallons of oil profit to shut down and repair the leak. They have a financial interest to not fix it.

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If i understand correctly, it was green. Meaning the next block was indeed clear but the other train was stopped in the same block and there aren't supposed to be 2 trains in the same block. That's the disagreement between the new virtual system and the old system.
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Why would they trust "a random blinking green light", but not a written and stamped order? Yes, they could do that (and sometimes it will actually prevent an accident), but it will be more being a snowflake, then being a decision for safety. A conductor is simply not responsible for whether it's safe to drive on a given track. Their equivalent is not a car driver.
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The "random blinking green light" is generally more reliable

Being a snowflake here has 2 benefits:

1. Getting company managing tracks to fix the lights (they need to deal with angry customers and pay off damages for delays and more), so there's a direct path from unreliable lights to economic damage.

2. Avoid crashing and killing yourself and passengers on the offchance the person on the radio is a moron

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> The "random blinking green light" is generally more reliable

Yes, but not because of the light itself, but due to the safety steps done before. Which should also have happened before the movement order in any other form.

As a train driver, you do not have the information required to distinguish these situations. If drivers simple refuse all movement orders, besides "green lights", running trains will become a rare occasion and the drivers will simply get fired for not doing their job. _The train driver is not the one who decides where a train goes._ For this safety-relevant decision a driver is (roughly speaking) nothing more than an innocent bystander.

You can think of a train driver more of the person who makes sure the automatic engine works correctly and also has an eye, that nothing weird happens. Most of your train driver education is knowing how the train works and how to get a broken train back working fast. In addition you also learn the safety protocols how you get the information in which state the engine should operate in. This is what train signals are, it's not really the equivalent of a green traffic light for car traffic.

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Actually in this case it looks like the error was that the light did show green, when it should be ignored: https://news.ycombinator.com/item?id=50298796
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Many train systems have a trip-stop on signals that will automatically activate the trains's emergency brake if one passes a red signal.

It cannot be bypassed, if an operator must go through a red they have to manually reset the e-brake on each car once it passes the signal.

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