Rail Chain Signals Need A Better Desciption

[AileTheAlien]

TL;DR

The descriptions for rail chain signals is misleading.

What?

The current description, "Reads the next signal in the path to allow better control of the trains." is misleading in some situations, and completely wrong in others. (I mean this, given the observable behaviour in the game. The UI could certainly do a better job of indicating the actual behaviour of the game logic, but I'll save that for another thread.)

Why?

This first example, is where the description seems to follow the behaviour of the signals:

description-matches-observable-bahaviour-1.png (426.6 KiB) Viewed 2181 times

The indicated signal appears to be reading the two other signals on the other paths, and all is well.

Here, we learn that chain signals work with multiple exits.

description-matches-observable-bahaviour-2.png (505.96 KiB) Viewed 2181 times

That makes sense - the description says "next signals", plural. Cool, that should come in handy with bypasses at unloading stations!

Now the first negative example; There are no other signals that have turned red, so the behaviour is confusing.

description-misleading-1.png (395.72 KiB) Viewed 2181 times

Is it acting like a normal signal in some situations? Does distance matter? Am I doing something wrong? Maybe it's several things! Since it's unknown how many things are wrong, I have to start debugging my trains, and also second-guessing the things the game has taught me about signals.

This example shows another problem.

description-misleading-2.png (488.8 KiB) Viewed 2181 times

When I first started placing signals directly opposite each other on tracks, and started experimenting with bi-directional tracks and single-direction tracks, I again had to learn what's going on. I might be unusual, but my first track was a big circle, since that's easier than lining up the rails for loops at the end of a bi-directional track. I'm also from North America, where trains are rare, and cars (single-direction roads!) are common. (I also suspect that the word "path" is partly to blame here. A "block" is unrelated to any type of transportation in the real world, but a "path" could have directionality. Foot-paths are bi-directional, but I'm accustomed to driving and navigating a car, which has directionality.) The game's UI also shows directionality to the signals, which adds to the problem; I learned that signals chain from signals that are pointing the same direction. That's wrong, but I also still don't know what the correct mental model is supposed to be for chain signals. I think it's supposed to be "Examine two blocks ahead of this signal instead of just two, but also keep in mind multiple exits like you learned before. The direction of the signals only matters for the trains, not the signals. Probably."

I actually went through the tutorials for train signals again before posting this; It didn't help. When nuclear power facilities are a simpler puzzle than trains, I think that's a problem. (Note that nuclear is higher in the tech tree, and yet again more complicated in real life. It should not be a simpler puzzle than trains!)

[Aeternus]

Not really. Nuclear power is simple compared to trains. Water + fuel in, power + waste out.
Trains form a mesh network with multiple destinations and individual train routing across a wide area with many possible routes.

But yes, the chain signal description should be changed. As I understand it, chain signals block a train until the path to the next free (non-virtual, IE by passing a normal signal or station) block on the train's route is guaranteed, then reserves that entire path once the train moves in it. This can prevent deadlocks by ensuring a train can clear an intersection all the way to the exit prior to allowing crossing traffic.

[Hedning1390]

Chain signals look at its own block but also at the next signal. A red signal overrules a green always, so a chain signal which looks at two things (the next signal and its own block) will be red if either is occupied.

Would a description like "Also reads the next signal in the path to allow better control of the trains." be more clear?

If you are unsure you can also go by the rule "signals will never allow trains to crash" which explains why the last two pictures are the way they are.

[runamucker]

Agreed. The description is incorrect and misleading. Chain signals were voodoo magic to me until I watched some really clear YouTube rail tutorials.

"Chain signals first read the block ahead for trains. If it's clear, they read the signal(s) that end the block."

[AileTheAlien]

Not really. Nuclear power is simple compared to trains.

I think my original phrasing was poor here. I was in fact saying that nuclear power in this game is a simple puzzle compared to trains, and actually linked to a video of somebody sharing the same sentiment. :)

Either way, the description is bad right now. (Also the tutorials, but I'll make a post for that if I have time to make better tutorial levels / setups.)