Train waiting area, why not use tracks with green lights

[Koekebakker]

Hi all,

I hope someone can help me with the following problem I have.
I've been playing Factorio for about a year now, used trains whenever I needed them, but always kept it simple.
But now I want to use more trains, just because I like them so much

My smelting area could use a lot of more ore (and I am planning on expanding the smelting are in the future), so I was thinking about it how to manage a lot more trains for unloading the ore.

I saw something on YouTube that I liked, so I kind of copied that idea.
It's a waiting area for trains that are full of cargo, and are waiting for a free unloading station. I think this is a good solution for my purpose.

But it doesn't work the way I would like, and I don't understand why. So maybe someone could help me see the problem.

The problem is simple. As you can see I have placed some wagons on the track to "simulate" some occupied blocks to create red lights.
Now at the bottom left the train with copper ore is arriving, but while there are green lights at the upper part, the train wants to take the bottom track, which has a red light.

So my question is why does the train want to take this route, and not a free track just above it?

Train waiting area

fatorio_train_waiting_area.jpg (342.57 KiB) Viewed 18703 times

[ratchetfreak]

because it decides on its route when it starts moving. and carriages don't have that much added weight to the cost (even though they should IMO)

If you precede the split with a chain signal then it should repath to take a free one.

[Koekebakker]

I've found the problem..... seems I didn't connect the rest of the track properly. But I couldn't see it the first time, because the train was waiting atop of it.
But I'll put a chain signal before the split. I was thinking about doing that.

Thanks for the help

fatorio_train_waiting_area_booboo.jpg (351.41 KiB) Viewed 18690 times

[Gus_Smedstad]

I've had a working station with a waiting area.

waiting area

It's important to note that I discovered that sometimes trains will insist on pathing through locked blocks. It's a matter of path length - if pathing around a locked block adds enough length after the choice, the train will ignore the free path.

Ignoring open block

In the above image, the train refuses to use block E because block G is longer than block B. So it tries to path through block B.

The one sure-fire solution is what I took in my first image - all paths are identical in length, it's guaranteed that trains will consider all of them. However, just making your waiting area blocks longer than the track merging them works too. Same setup as the above, but longer blocks, and the train uses block E.

Longer blocks

[johanwanderer]

It's important to note that I discovered that sometimes trains will insist on pathing through locked blocks. It's a matter of path length - if pathing around a locked block adds enough length after the choice, the train will ignore the free path.

Ignoring open block

In the above image, the train refuses to use block E because block G is longer than block B. So it tries to path through block B.

The one sure-fire solution is what I took in my first image - all paths are identical in length, it's guaranteed that trains will consider all of them. However, just making your waiting area blocks longer than the track merging them works too. Same setup as the above, but longer blocks, and the train uses block E.

Longer blocks

For longer blocks, just chain another signal to them (i.e. between your current chain signal and the longest block). That way the signal can be propagated all the way to the entrant signal.

[Gus_Smedstad]

For longer blocks, just chain another signal to them (i.e. between your current chain signal and the longest block). That way the signal can be propagated all the way to the entrant signal.

Propagating the signal, as you put it, is not the problem, or even required. My experience is that chain signals don't have a distance limit, they look to the next signal no matter how far ahead it is, so adding an additional chain signal along the same stretch of track with no track switches involved does absolutely nothing. The problem is the way trains path through locked blocks based on path length.