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Efficient train crossings (deadlocks, halts, wait time)

Posted: Sat Apr 18, 2015 1:18 pm
by SHiRKiT
So, I know this can be solved in 0.12 Chain Signals but I want to share my creations thus far, and have some feedback upon other people's designs as well.

I have so far came up with 3 different designs of crossings.

https://dl.dropboxusercontent.com/u/327 ... .59.41.png
Image
Explanation:

- The bottom left one is my standard crossing design I do at the start of the game. It's cheap, it's fast to be manually built, and it's simple to remember. It's dumb since often locks up if a train stops a part of it inside the circle while waiting to go at the another station. This can be solved by moved the station, but still annoys me.

- The top left design is an improved version of the bottom one. I do it when I have bots constructing things for me. It saves train distance a bit and it looks cool.

- The right design is the current design I'm trying, but no matter what I do, I cannot optimize the design without causing deadlocks.

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What I'm trying to achieve is (let's imagine the crossing on the right):
- If a train comes from the bottom to the top, I want a train from the top to the bottom to be able to cross without a slowdown (not currently possible). The same goes for right->left and left->right at the same time.
- If a train comes from any direction and want to do a 90º right turn, it shouldn't block any other train coming at the crossing (except a train behind it, of course).
- If a train want to do a turn around, it should block only the entrances that it's going at that time (deadlock magnet). A solution is to provide a turnaround that's isolated from the rest of the crossing. Maybe it's fine to accept a global signal block? (this would slowdown everything)
- If a train wants to do a 90º left turn, it should behave as a turnaround. That means should block the least possible entrances, but maybe it's inevitable to block everything.
- Must be able to do a 4-way intersection.
- Must carry power.

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So, can you guys share your own crossings? Or give me some tips onto this?

Small note: Also, if you want to know why the right crossing has 2 tracks at every direction is that I'm trying to see if a "express highway" helps me deal long distance traveling. I wanted to do something like a real life highway, where no train can stop at it, and it only connects to highways, and the entry/exit points are at the intersections. The only downside is that I cannot set the inner tracks to have a "lower weight" to the pathfinder algorithm. Maybe creating a "High-speed track" would help me deal with this issue.

Re: Efficient train crossings (deadlocks, halts, wait time)

Posted: Sat Apr 18, 2015 1:27 pm
by DaveMcW
Bottom left is the best you can do without chain signals. Everything else is a fancy version of it, or prone to deadlock.

You just need to give your trains more space.

Re: Efficient train crossings (deadlocks, halts, wait time)

Posted: Sat Apr 18, 2015 1:45 pm
by SHiRKiT
DaveMcW wrote:Bottom left is the best you can do without chain signals. Everything else is a fancy version of it, or prone to deadlock.

You just need to give your trains more space.
Sorry but I can't be satisfied with that :D Not that I think that you are wrong or something, but I can't give up searching for a solution! :D I must find a solution!

Edit:

This is where I am hahaahahahhahaha Look at this mess!

https://dl.dropboxusercontent.com/u/327 ... .00.21.png
LOL AT THIS

Re: Efficient train crossings (deadlocks, halts, wait time)

Posted: Sun Apr 19, 2015 2:07 am
by ssilk
I keep at my opinion, that currently (and I think even with the new chain signals) the most efficient crossing in Factorio is with three tracks:
https://forums.factorio.com/forum/vie ... cks#p73635
* Don't use 4-way junctions or circles to create junctions.
* Use better 3-way junctions. See https://forums.factorio.com/forum/vie ... =18&t=9044 A Detailed Look at a Bidirectional Three-way Train Intersection
* Use circles only for changing direction of train
* Build more tracks around junctions. try to avoid jams around junctions. If that doesn't help, use more tracks. :)
See also
https://forums.factorio.com/wiki/inde ... /Deadlocks
https://forums.factorio.com/forum/vie ... =18&t=9044
https://forums.factorio.com/forum/vie ... 746#p58700
https://forums.factorio.com/forum/vie ... =18&t=5434

Re: Efficient train crossings (deadlocks, halts, wait time)

Posted: Sun Apr 19, 2015 12:41 pm
by DaveMcW
16rail.jpg
16rail.jpg (260 KiB) Viewed 3770 times

Re: Efficient train crossings (deadlocks, halts, wait time)

Posted: Sun Apr 19, 2015 1:03 pm
by SHiRKiT
I think it's something inevitable to have slowdown on junctions =\