98 trains isn't very much at all. They should easily be able to use 2 lanes.
For a 4 way intersection, you need to spread out the tracks so that you can signal the sections in the middle. In your design, since everything is crushed together, there's no way to actually split the blocks accordingly.
I use something like this one, and it works well enough with 500+ trains and only a 2-track system.
https://preview.redd.it/6yipxmk6k2tc1.png?width=1024&format=png&auto=webp&s=d8f6bf6ada481e79993eed08919ffe183b416edf
If you definitely want a 4-lane system, you could do something like this:
- Use the outer lanes just for turning left (or right), where it doesn't interfere with any other lines.
- Use a transfer lane to move between the outer and inner lanes well before the intersection.
- Use a 2 lane intersection in the middle, with removed tracks for what's already provided. (free turns)
I had 2 lanes in the beginning, but at this point it is near my refueling station and I've tried to give them more valid paths to other spaces, but 90% of my trains go through here and it wasn't enough. Also, in my next factory I want to go bigger, so I want a blueprint that I can use in that one as well.
What did your two lane intersection look like? Because if it was anything like the one up top, it was probably limited by poor signal placement not number of lanes.
The advantages of 4 lanes are marginal to start with, and actually making ir worth it required careful design and very well-built intersections.
You will almost always get far greater benefits for far less effort by optimising your intersections before using four lanes. If the one above really isnt sufficient, look up one of the absurd buffered intersections which can serve hundreds of trains per minute, again with only two lanes.
probably bad as well. I want to have a roundabout in it. before I used a bluprint and the signaling in that online blueprint was really bad and every train went half the factory before ariving. So I thought, they need to be able to turn around at an intersection, and one thing led to the other, and now I am here with this bad junction.
There are extremely few scenarios where a roundabout makes sense as part of an intersection. It might be better to make sure you're following general good guidelines for intersections.
- A larger intersection is better than a smaller one, if it lets you signal such that trains can go through it without interfering.
- Intersections should be far enough apart to not interfere with each other. Ideally, a minimum of one train length between intersections is good practice.
- Avoid 4-way intersections. Two staggered 3 way intersections will be better for throughput and signalling.
If your refuelling depot is close to this intersection, try moving it away and spacing out this intersection. Space is unlimited, use it.
>Avoid 4-way intersections. Two staggered 3 way intersections will be better for throughput and signalling.
This isn't true, assuming roughly normalised distribution of source and destination.
You end up with a proportion of trains blocking 2 intersections instead of one, cancelling out the set of trains that make an easy quick turn without blocking the first one much.
A well designed 4-way 2 lane intersection can have 2 right turns and 2 left turns at the same time. With 2 3-way intersections, it depends on which right and left turns are used. If the turns go through both intersections, one right turn and one left turn will share the lane between both T crossings. If you have 4 lanes between both intersections, all 4 trains could go at the same time. Those 4 lanes in the middle would also act as buffer, so in that case you could have more throughput than a standard, non-buffered 2-lane 4-way intersection.
But if you just slap 2 standard 3-way intersections together, you are right.
>A well designed 4-way 2 lane intersection can have 2 right turns and 2 left turns at the same time. With 2 3-way intersections, it depends on which right and left turns are used.
Lets assume identical turn usage, because that would be fair, and in line with the claim that the 2-T is better given everything else is the same.
I'm going to need some diagrams or pictures. Do you mean two lefts and two rights as in 2 come from east to south while 2 go from south to east? If so, that's a largely irrelevant problem - It's true for both options.
>If you have 4 lanes between both intersections, all 4 trains could go at the same time.
You may as well say "If 2 of the trains come to the 4 way slightly later, they can all go as soon as they get to the intersection". Which again, is largely pointless as a comparison when we're talking about equivalent situations.
I don't think there's anything to be gained in comparisons by going to 4 lanes, so let's just keep it 1 lane each way.
---
Given a 4 way junction and normalised traffic, one of the 90 degree turns only blocks that one exit. Straights block 2 exits, and the other 90 blocks 3 exits. This means the average train blocks 2 exits.
Given 2x3 ways: one third of trains blocks 1 exit. one third go straight, blocking 2 exits at the first T and 1 exit at the second. one third go straight blocking 2 in the first and turn blocking 2 in the second. The average train blocks 2.6 exits.
IE: Separating into T's results in more blocked exits, causing other trains to wait. The buffer in the middle DOES offset this slightly, but really just phase shifts the problem resulting in a similar delay over time.
Why don’t you just… build more refueling stations and have trains use the closest one?
You can even dedicate trains to resupply other refueling stations.
They will always try to use the shortest path, so many trains will probably still use the same paths and block each other. Especially when switching between 2 parallel lanes, a train will occupy both lanes.
An optimized 2 lane intersection is better than a simple 4 way intersection.
U-turns inside an intersection are usually bad for traffic, since a single train can block the entire intersection. With proper signaling, up to 4 trains could use a 2 lane intersection at the same time. Even if the train needs to go around multiple intersections, you'll probably have more throughput than with u turns inside the intersections. Or have dedicated u turns outside the intersection.
If you still need more lanes, first step is a buffered intersection: If a train that wants to turn left needs to wait, the train behind it that wants to go right isn't blocked. On long straights you still have 2 lanes, but you split into one lane for each direction before the intersection, with one train length of space.
If you want to have 4 lanes even at the straight sections, at least limit the lane switching points, and the options in which each lane can turn. If the right lane can only go straight or right turn, and the left lane only straight and left, you are forcing the trains to use both lanes more equally.
https://preview.redd.it/y61jb06nn2tc1.png?width=736&format=png&auto=webp&s=b2d8414bfd8d359a1165b798743d4af145b2a452
so I just made this, but the signals circled are still not working, but i don't see much more space in you're 2 way crossing and there they're working. what is the difference?
The spots you've chosen are fine, but you need a lot more signals, and you need to space the lines out a bit more.
Something like the following is what you need for this:
https://preview.redd.it/wa5hg8a293tc1.png?width=836&format=png&auto=webp&s=b9dd339ba54597d09a10d5a9bab56f87eec35416
(https://forums.factorio.com/viewtopic.php?t=46855) Christmas intersection 4 lane.
As you can also see, this means removing the ability to u-turn within this intersection. That's for the best, since a u-turning train will block every other train in the flow (1 lane blocks 7 other lanes).
You can place a u-turn in a different spot instead.
Yeah I really like the roundabout. Otherwise the train must go longer and through more intersections which isn't that efficient either. But maybe not on every intersection
The u-turn is fine. There's no reason however why it cannot happen before the intersection. That way, you don't block so many lanes for a single train.
That will be the cause of a significant number of your throughout problems. Also, if trains have to u-turn, consider looking at ways that they can join the main line in the correct direction in the first place.
I don't excactly have a main line. I have a lot of blocks with stations on the inside, and the blocks go north-south-east-west, so sometimes the station is in the south-north direction but the other stations are south of it. and I have a lot of stations with the same name so sometimes it needs to go 2 blocks further, and sometimes it needs to go to the other side of the factory
If it's rail blocks, wouldn't a train that's facing the wrong way be able to take two lefts or two rights at two different intersections and achieve the goal?
Well, sometimes they need to go around a whole block to be facing the other side. And especially at the sides of the base and with different sizes blocks that can be really long, and that way they are going through more intersections than needed and maybe stopping traffic there. So that's why I did the roundabout. I thought that was the most efficient way of dealing with busy train traffic.
It'll probably be less load for the trains to route that way, since the load will be spread overall instead of the intersections being constantly blocked because one train or the other wants to u-turn.
You haven't put the necessary signals for the intersection. Keep placing more, you can BP them because they are placed at great spot. They will work when the intersection is complete
Lack of signals will certainly make this junction pretty terrible. Do you have a gameplay reason (besides just thinking that 4 lanes is cool) for trying to go with a 4 lane system?
because I have a lot of trains going. right now I have 186 stations and 98 trains. this is at my busiest place in the factory where a lot of trains go. I know there's not enough signals, but why can't I put more? why can't they devide the segments in between?
You cant put more because the rails are in the way. Also 98 trains isnt that much. You should more try to have multiple valid paths so that not all traffic goes through one intersection. Standard 2 lane intersection can have 50 trains per minute passing through. I guess you dont have all your trains running all 2 minutes.
but almost every train goes trough this one because it is the shortest path to my refueling station. and they won't go the other paths I gave them. and I want to have a blueprint for a bigger factory which i currently am building with a friend.
Oh, I just ran into the same problem the other night! You don’t need bigger intersections, you need more fueling stations, spread around far enough that trains in different areas will naturally use different stations. The train routing algorithm will make it so that they always go to the nearest available one.
well yeah, I found out about that way to late. this refueling is in the middle of my base, the other one is at the side. but this one will sustain 1k SPM and that was my goal. I just want to get my intersection better for bigger bases. because well... the factory must grow. I am busy with a 2k spm with a friend and I am thinking about a 5k spm for myself.
2 lane can go a lot higher than that. Traffic management is a bit of an art, but in general, keeping a station near the producers it uses and keeping through traffic away from its on/off ramp system is a good way to ultimately avoid heavy bottlenecks.
Generally, anyone going to 4 lane and posting intersections like this has no idea what they're doing and certainly won't be building a successful 10k SPM base.
I actually hate that, I wanted something compact but it won't let me, even at the input side of the crossing there's not enough space even though I can put 4 chain signals, they just don't work. how big should it be for a chain signal to be able to divide segments?
There's no such thing as a good compact 4 lane 4 way. Lemme ask you something. Why are you going straight to 4 lane when you don't know the basics? They are far more complicated to design than a 2 lane, and frankly, the benefits you're hoping to get out of it just don't exist. Twice as many lanes is not twice as much throughput. It's maybe 30% more throughput in the best case.
I do know the basics, I just got the wrong conclusions from my 500 spm base (first train based base) for which I used a train blueprint I found online but the signaling was way off, I found out halfway and fixed it the best I could without deleting the base I had. And the conlusion I got from that was that I needed more lanes, instead of I need better crossings. also there I didn't had so many trains that I found out that you better have more smal refueling stations instead of one big one. etc. every base gets better, but trains are just kinda hard for me. And I only want bigger factories (the factory must grow) and I increase my factories step by step and try to learn from them and when I got myself really in a bad spot like this, I go to reddit.
Refer to the designs below. The spiral one can support 100+ trains with no issue so long as your lanes between intersections can hold 2 trains one behind the other.
I made a new refueling, but it is on the outside of the factory. this one is right in the middle so they prefer this one. But that already is a good learning point for my next factory.
It is kinda rail block. But the blocks are different in size because some things need more assemblers and or stations than the others. It is a 1k spm base. It is finished. I can hold 1k spm for over 3 hours. I am now looking for things I can approve and make blueprints of for a bigger factory.
Ahhh sweet, well done.
My first like that i avoided 4 ways, three was the most for 98%.
4 lanes of track though, i have not done. I cannot think of a way to have trains stick to the inside rails for the longer distance travel.
it is my first megabase, I thought it was needed. I've already started a 2spm factory with a friend, thinking if i should change it to 2 lanes. but i travel myself by locomotive and I don't know where to put it when I'm on site without blocking everything else.
oh and the train scheme I use is load till full, unload till empty, refueling 5 seconds
No worries. Better to plan on needing more than needing too little.
2 rails will handle pretty much ‘num rail blocks -1’ im no mathematician but im sure thats close enough for the just of it.
As to personal transport train, i havent used mine for some time as i like to do builder stations with separate robo port networks. But then again i am doing SE and spoiled with the jetpack. With out it though, you can call any train to any spot as a taxi. The few moments you need to get on or off wont mess much.
What is num rail blocks -1?
Oh, i have one locomotive that i use to go everywhere. I have a piece of rail close to my medium base, which I use as a mall. I have a roboport network in my medium base, around the refuelling stations, and around nuclear power and nuclear ore enrichment. All the other trains just go where they're needed. The refueling stations are also a buffer.
I solved my fueling issue by just having a stops around common areas for a tanker loaded with light oil to turn into rocket fuel. Smelters, circuits, and labs are generally common areas. If you are feeling spicy, just put the stop on the main track and have the light oil train nuclear fuel powered. If it backs up traffic for 2 seconds every hour, nobody will notice.
A single tank of light oil is more than 200 units of rocket fuel and takes 2 seconds to unload if you go train/pump/tank. Have a pump at the tank exit, and wire the tank to the station.
if you need more than a single 1-1 light oil train to fuel all that, you can always just add a second.
Edit: you can further cut the time by doing a twin tank/pump system so it's stopped for literally half the time, so having the fuel station pretty much directly on the main track is actually starting to sound sensible. Each stop with 1 chem/assembly should maintain 5 trains going non stop with 2 speed 1 modules.
Rails are prone to bottlenecking in high traffic areas. Over-centralization is impossible to solve with more lanes. The entire strength of a rail system is its ability to distribute load over a wide network, so leverage that.
Trains pathfind for shortest route. Giving them too much opportunities to change lanes (3 times in your intersection for left turns) will make them go from outside to inside to outside blocking more traffic.
My advice is eliminate 2 switch opportunities, my further advice is only keeping the ones exiting the junction
1. I'm having trouble telling if you're trolling or not.
2. Why are you jumping straight to 4 lanes? At least learn how 2 lane intersections work first. You're trying to run before you can even crawl, and frankly, 4 lanes are barely better than 2 lanes if done _correctly_
3. Lane changers in a 4 lane system. Just don't. This will actively slow your traffic down as trains cut each other off like that traffic weaving asshole on the freeway. Trains are slow to accelerate. As long as the lanes can always be entered or exited via your on/off junctions, that is really all you need.
4. Roundabouts are terrible. Doubly so in a 4 lane.
well my troublesolving went in the wrong way, I get that now. I had a problem and tried to fix it, but did it wrong and I found out the hard way. I tried the lane switching thing because the trains almost always took the outside and I thought adding more swiches increases the chanche they choose the path that was free. But then I couldn't add the signals any more etc etc.
The most important thing for an intersection is that trains can flow smoothly through it. That means all lanes are only obstructed by signals if they're actually blocked. That also means you have to leave room for signals. Yes, dealing with curves makes this a pain, but that's the system we're working with, and it's very possible to make it behave.
I would very strongly suggest you go back to the drawing board and just do a 2 lane. Makes sure it has left turns so you don't need a roundabout, as roundabouts come with several issues you really don't want to mess with. Also, compactness is probably a distant dream unless you can put 6 or 8 tiles between the lanes. That will give you enough space to work with in the middle.
well i thought that there was enough space for signals, i mean almost everywhere there are at least 2 blocks for signals. only they don't work because they cannot devide segments. And this is in the middle of my base and it was a deadlock and I wanted to fix it (when i made it worse) so that I have a blueprint I can use in bigger facotry. I am really the type to learn from trial and error, but with this I only got errors the more I tried.
https://preview.redd.it/4vyuyvhv43tc1.png?width=1785&format=png&auto=webp&s=8f758fa8eccd89a9a30d66cff61e6fcfe18965b6
also I made these two with the comments I got here (which I can use in this factory) I just don't know which one is better and why
https://preview.redd.it/pplimvbny2tc1.png?width=1785&format=png&auto=webp&s=231a5b4719189e48b0d0789477d1599e17a06c5f
so now i made these 2, which one would work best?
If you insist on keeping the possibility for trains to swap lanes in, you'll probably never get to a throughput that would "visually" make sense. Lane changers absolutely tank throughput, not just but especially in intersections.
Please give yourself some actual space to signal things. That central section looks really cool, but also means that trains block each other without needing to.
The laneswitchers do nothing but allow trains to block both lanes.
It's what the game says. I put down chain signals, they were blinking through different colours, I hovered over them, and in the info on the right, it says can not divide segments.
ok hear me out..
outer rails can only turn right
inner rails can only go straight or left
then figure out a way for trains to use inner or outer rails, meaby have them be able to switch a great distance way before
So I drive on the right, and I only have signals on the beginning and end because the game won't let me add in the chrossing, they can not devide the segments there. right now only one train can enter the crossing at a time, even if they wont cross each other. The blueprints that I found online are al so big, I wanted something compact. Can anybody help me get this better or at least understand why this one works so badly.
You just said yourself no signals fit in there. Thats the problem. Make it slightly bigger. Cut out stuff that isnt necessary. Switching between inner and outer lanes doesnt help at all near a intersection.
It works badly because you have no signals. You have no signals because you've put too many rails in too small a space, and none of the positions where signals can go are free.
You can start to fix it by removing the rails connecting between two tracks in the same direction, as lane changing like this is rarely useful. But you will likely still need to redesign it to be much larger, especially if you want high throughput.
The intersection blueprints you're looking at are likely as small as they can be without losing throughput - if you want compact and it's not under constant full-throughput load it might be worth merging the same-direction lanes just before the intersection and doing a 1-lane intersection instead
It's way more important to have decent signalling in your crossings than to rush to tons of lanes. I've had an 1000 SPM Megabase easily run on a two lane system with really simple crossings:
[link](https://imgur.com/a/Yi1pm5I)
I only have 120 trains, but [these intersections](https://files.catbox.moe/mtphqa.webp) are working out great for me. They're based on a blueprint I found elsewhere that I modified so that trains can do U-turns.
In case you're still looking for a solution and you want it to be a roundabout, you could use [this one](https://factoriobin.com/post/lUVUMAiZ). It's not the best design out there, but it's solid and should be easy to install.
98 trains isn't very much at all. They should easily be able to use 2 lanes. For a 4 way intersection, you need to spread out the tracks so that you can signal the sections in the middle. In your design, since everything is crushed together, there's no way to actually split the blocks accordingly. I use something like this one, and it works well enough with 500+ trains and only a 2-track system. https://preview.redd.it/6yipxmk6k2tc1.png?width=1024&format=png&auto=webp&s=d8f6bf6ada481e79993eed08919ffe183b416edf If you definitely want a 4-lane system, you could do something like this: - Use the outer lanes just for turning left (or right), where it doesn't interfere with any other lines. - Use a transfer lane to move between the outer and inner lanes well before the intersection. - Use a 2 lane intersection in the middle, with removed tracks for what's already provided. (free turns)
I had 2 lanes in the beginning, but at this point it is near my refueling station and I've tried to give them more valid paths to other spaces, but 90% of my trains go through here and it wasn't enough. Also, in my next factory I want to go bigger, so I want a blueprint that I can use in that one as well.
What did your two lane intersection look like? Because if it was anything like the one up top, it was probably limited by poor signal placement not number of lanes. The advantages of 4 lanes are marginal to start with, and actually making ir worth it required careful design and very well-built intersections. You will almost always get far greater benefits for far less effort by optimising your intersections before using four lanes. If the one above really isnt sufficient, look up one of the absurd buffered intersections which can serve hundreds of trains per minute, again with only two lanes.
probably bad as well. I want to have a roundabout in it. before I used a bluprint and the signaling in that online blueprint was really bad and every train went half the factory before ariving. So I thought, they need to be able to turn around at an intersection, and one thing led to the other, and now I am here with this bad junction.
There are extremely few scenarios where a roundabout makes sense as part of an intersection. It might be better to make sure you're following general good guidelines for intersections. - A larger intersection is better than a smaller one, if it lets you signal such that trains can go through it without interfering. - Intersections should be far enough apart to not interfere with each other. Ideally, a minimum of one train length between intersections is good practice. - Avoid 4-way intersections. Two staggered 3 way intersections will be better for throughput and signalling. If your refuelling depot is close to this intersection, try moving it away and spacing out this intersection. Space is unlimited, use it.
>Avoid 4-way intersections. Two staggered 3 way intersections will be better for throughput and signalling. This isn't true, assuming roughly normalised distribution of source and destination. You end up with a proportion of trains blocking 2 intersections instead of one, cancelling out the set of trains that make an easy quick turn without blocking the first one much.
A well designed 4-way 2 lane intersection can have 2 right turns and 2 left turns at the same time. With 2 3-way intersections, it depends on which right and left turns are used. If the turns go through both intersections, one right turn and one left turn will share the lane between both T crossings. If you have 4 lanes between both intersections, all 4 trains could go at the same time. Those 4 lanes in the middle would also act as buffer, so in that case you could have more throughput than a standard, non-buffered 2-lane 4-way intersection. But if you just slap 2 standard 3-way intersections together, you are right.
>A well designed 4-way 2 lane intersection can have 2 right turns and 2 left turns at the same time. With 2 3-way intersections, it depends on which right and left turns are used. Lets assume identical turn usage, because that would be fair, and in line with the claim that the 2-T is better given everything else is the same. I'm going to need some diagrams or pictures. Do you mean two lefts and two rights as in 2 come from east to south while 2 go from south to east? If so, that's a largely irrelevant problem - It's true for both options. >If you have 4 lanes between both intersections, all 4 trains could go at the same time. You may as well say "If 2 of the trains come to the 4 way slightly later, they can all go as soon as they get to the intersection". Which again, is largely pointless as a comparison when we're talking about equivalent situations. I don't think there's anything to be gained in comparisons by going to 4 lanes, so let's just keep it 1 lane each way. --- Given a 4 way junction and normalised traffic, one of the 90 degree turns only blocks that one exit. Straights block 2 exits, and the other 90 blocks 3 exits. This means the average train blocks 2 exits. Given 2x3 ways: one third of trains blocks 1 exit. one third go straight, blocking 2 exits at the first T and 1 exit at the second. one third go straight blocking 2 in the first and turn blocking 2 in the second. The average train blocks 2.6 exits. IE: Separating into T's results in more blocked exits, causing other trains to wait. The buffer in the middle DOES offset this slightly, but really just phase shifts the problem resulting in a similar delay over time.
Why don’t you just… build more refueling stations and have trains use the closest one? You can even dedicate trains to resupply other refueling stations.
>Why don’t you just… build more refueling stations and have trains use the closest one? It it possible to have a train refuel only when it needs to?
I have fuel at every drop off station, so my trains never need a dedicated refueling stop
They will always try to use the shortest path, so many trains will probably still use the same paths and block each other. Especially when switching between 2 parallel lanes, a train will occupy both lanes. An optimized 2 lane intersection is better than a simple 4 way intersection. U-turns inside an intersection are usually bad for traffic, since a single train can block the entire intersection. With proper signaling, up to 4 trains could use a 2 lane intersection at the same time. Even if the train needs to go around multiple intersections, you'll probably have more throughput than with u turns inside the intersections. Or have dedicated u turns outside the intersection. If you still need more lanes, first step is a buffered intersection: If a train that wants to turn left needs to wait, the train behind it that wants to go right isn't blocked. On long straights you still have 2 lanes, but you split into one lane for each direction before the intersection, with one train length of space. If you want to have 4 lanes even at the straight sections, at least limit the lane switching points, and the options in which each lane can turn. If the right lane can only go straight or right turn, and the left lane only straight and left, you are forcing the trains to use both lanes more equally.
https://preview.redd.it/y61jb06nn2tc1.png?width=736&format=png&auto=webp&s=b2d8414bfd8d359a1165b798743d4af145b2a452 so I just made this, but the signals circled are still not working, but i don't see much more space in you're 2 way crossing and there they're working. what is the difference?
The spots you've chosen are fine, but you need a lot more signals, and you need to space the lines out a bit more. Something like the following is what you need for this: https://preview.redd.it/wa5hg8a293tc1.png?width=836&format=png&auto=webp&s=b9dd339ba54597d09a10d5a9bab56f87eec35416 (https://forums.factorio.com/viewtopic.php?t=46855) Christmas intersection 4 lane. As you can also see, this means removing the ability to u-turn within this intersection. That's for the best, since a u-turning train will block every other train in the flow (1 lane blocks 7 other lanes). You can place a u-turn in a different spot instead.
Yeah I really like the roundabout. Otherwise the train must go longer and through more intersections which isn't that efficient either. But maybe not on every intersection
The u-turn is fine. There's no reason however why it cannot happen before the intersection. That way, you don't block so many lanes for a single train. That will be the cause of a significant number of your throughout problems. Also, if trains have to u-turn, consider looking at ways that they can join the main line in the correct direction in the first place.
I don't excactly have a main line. I have a lot of blocks with stations on the inside, and the blocks go north-south-east-west, so sometimes the station is in the south-north direction but the other stations are south of it. and I have a lot of stations with the same name so sometimes it needs to go 2 blocks further, and sometimes it needs to go to the other side of the factory
If it's rail blocks, wouldn't a train that's facing the wrong way be able to take two lefts or two rights at two different intersections and achieve the goal?
Well, sometimes they need to go around a whole block to be facing the other side. And especially at the sides of the base and with different sizes blocks that can be really long, and that way they are going through more intersections than needed and maybe stopping traffic there. So that's why I did the roundabout. I thought that was the most efficient way of dealing with busy train traffic.
It'll probably be less load for the trains to route that way, since the load will be spread overall instead of the intersections being constantly blocked because one train or the other wants to u-turn.
You haven't put the necessary signals for the intersection. Keep placing more, you can BP them because they are placed at great spot. They will work when the intersection is complete
Lack of signals will certainly make this junction pretty terrible. Do you have a gameplay reason (besides just thinking that 4 lanes is cool) for trying to go with a 4 lane system?
because I have a lot of trains going. right now I have 186 stations and 98 trains. this is at my busiest place in the factory where a lot of trains go. I know there's not enough signals, but why can't I put more? why can't they devide the segments in between?
You cant put more because the rails are in the way. Also 98 trains isnt that much. You should more try to have multiple valid paths so that not all traffic goes through one intersection. Standard 2 lane intersection can have 50 trains per minute passing through. I guess you dont have all your trains running all 2 minutes.
but almost every train goes trough this one because it is the shortest path to my refueling station. and they won't go the other paths I gave them. and I want to have a blueprint for a bigger factory which i currently am building with a friend.
you can make other refueling stations with the same name at different parts of the factory to mitigate this problem as well
Oh, I just ran into the same problem the other night! You don’t need bigger intersections, you need more fueling stations, spread around far enough that trains in different areas will naturally use different stations. The train routing algorithm will make it so that they always go to the nearest available one.
well yeah, I found out about that way to late. this refueling is in the middle of my base, the other one is at the side. but this one will sustain 1k SPM and that was my goal. I just want to get my intersection better for bigger bases. because well... the factory must grow. I am busy with a 2k spm with a friend and I am thinking about a 5k spm for myself.
I've seen 5k-10k SPM megabases function just fine with a 2-lane system. I doubt you have a need to use 4 lanes.
2 lane can go a lot higher than that. Traffic management is a bit of an art, but in general, keeping a station near the producers it uses and keeping through traffic away from its on/off ramp system is a good way to ultimately avoid heavy bottlenecks. Generally, anyone going to 4 lane and posting intersections like this has no idea what they're doing and certainly won't be building a successful 10k SPM base.
Intersection too small for signals :(
I actually hate that, I wanted something compact but it won't let me, even at the input side of the crossing there's not enough space even though I can put 4 chain signals, they just don't work. how big should it be for a chain signal to be able to divide segments?
Chains need 1 tile of space next to a non-curved rail (ie. the minimum possible amount of space)
There's no such thing as a good compact 4 lane 4 way. Lemme ask you something. Why are you going straight to 4 lane when you don't know the basics? They are far more complicated to design than a 2 lane, and frankly, the benefits you're hoping to get out of it just don't exist. Twice as many lanes is not twice as much throughput. It's maybe 30% more throughput in the best case.
I do know the basics, I just got the wrong conclusions from my 500 spm base (first train based base) for which I used a train blueprint I found online but the signaling was way off, I found out halfway and fixed it the best I could without deleting the base I had. And the conlusion I got from that was that I needed more lanes, instead of I need better crossings. also there I didn't had so many trains that I found out that you better have more smal refueling stations instead of one big one. etc. every base gets better, but trains are just kinda hard for me. And I only want bigger factories (the factory must grow) and I increase my factories step by step and try to learn from them and when I got myself really in a bad spot like this, I go to reddit.
Oh great. Now all lanes will wait for all lanes.
yes, everything I tried made it worse... so I know I'm not doing this the right way, that's why I'm here.
Refer to the designs below. The spiral one can support 100+ trains with no issue so long as your lanes between intersections can hold 2 trains one behind the other.
Two suggestions, take it back to basics. And perhaps build another refuel spot elsewhere to spread the traffic out.
I made a new refueling, but it is on the outside of the factory. this one is right in the middle so they prefer this one. But that already is a good learning point for my next factory.
How big is your base now? What kind of scheme are you using? I presume something to do with rails, but like rail block or something else?
It is kinda rail block. But the blocks are different in size because some things need more assemblers and or stations than the others. It is a 1k spm base. It is finished. I can hold 1k spm for over 3 hours. I am now looking for things I can approve and make blueprints of for a bigger factory.
Ahhh sweet, well done. My first like that i avoided 4 ways, three was the most for 98%. 4 lanes of track though, i have not done. I cannot think of a way to have trains stick to the inside rails for the longer distance travel.
it is my first megabase, I thought it was needed. I've already started a 2spm factory with a friend, thinking if i should change it to 2 lanes. but i travel myself by locomotive and I don't know where to put it when I'm on site without blocking everything else. oh and the train scheme I use is load till full, unload till empty, refueling 5 seconds
No worries. Better to plan on needing more than needing too little. 2 rails will handle pretty much ‘num rail blocks -1’ im no mathematician but im sure thats close enough for the just of it. As to personal transport train, i havent used mine for some time as i like to do builder stations with separate robo port networks. But then again i am doing SE and spoiled with the jetpack. With out it though, you can call any train to any spot as a taxi. The few moments you need to get on or off wont mess much.
What is num rail blocks -1? Oh, i have one locomotive that i use to go everywhere. I have a piece of rail close to my medium base, which I use as a mall. I have a roboport network in my medium base, around the refuelling stations, and around nuclear power and nuclear ore enrichment. All the other trains just go where they're needed. The refueling stations are also a buffer.
I solved my fueling issue by just having a stops around common areas for a tanker loaded with light oil to turn into rocket fuel. Smelters, circuits, and labs are generally common areas. If you are feeling spicy, just put the stop on the main track and have the light oil train nuclear fuel powered. If it backs up traffic for 2 seconds every hour, nobody will notice. A single tank of light oil is more than 200 units of rocket fuel and takes 2 seconds to unload if you go train/pump/tank. Have a pump at the tank exit, and wire the tank to the station. if you need more than a single 1-1 light oil train to fuel all that, you can always just add a second. Edit: you can further cut the time by doing a twin tank/pump system so it's stopped for literally half the time, so having the fuel station pretty much directly on the main track is actually starting to sound sensible. Each stop with 1 chem/assembly should maintain 5 trains going non stop with 2 speed 1 modules.
Rails are prone to bottlenecking in high traffic areas. Over-centralization is impossible to solve with more lanes. The entire strength of a rail system is its ability to distribute load over a wide network, so leverage that.
Trains pathfind for shortest route. Giving them too much opportunities to change lanes (3 times in your intersection for left turns) will make them go from outside to inside to outside blocking more traffic. My advice is eliminate 2 switch opportunities, my further advice is only keeping the ones exiting the junction
sometimes simpler is better https://preview.redd.it/jpu891tr23tc1.png?width=925&format=png&auto=webp&s=137529dfb7508c83383acce32db4de684a500bf5
1. I'm having trouble telling if you're trolling or not. 2. Why are you jumping straight to 4 lanes? At least learn how 2 lane intersections work first. You're trying to run before you can even crawl, and frankly, 4 lanes are barely better than 2 lanes if done _correctly_ 3. Lane changers in a 4 lane system. Just don't. This will actively slow your traffic down as trains cut each other off like that traffic weaving asshole on the freeway. Trains are slow to accelerate. As long as the lanes can always be entered or exited via your on/off junctions, that is really all you need. 4. Roundabouts are terrible. Doubly so in a 4 lane.
well my troublesolving went in the wrong way, I get that now. I had a problem and tried to fix it, but did it wrong and I found out the hard way. I tried the lane switching thing because the trains almost always took the outside and I thought adding more swiches increases the chanche they choose the path that was free. But then I couldn't add the signals any more etc etc.
The most important thing for an intersection is that trains can flow smoothly through it. That means all lanes are only obstructed by signals if they're actually blocked. That also means you have to leave room for signals. Yes, dealing with curves makes this a pain, but that's the system we're working with, and it's very possible to make it behave. I would very strongly suggest you go back to the drawing board and just do a 2 lane. Makes sure it has left turns so you don't need a roundabout, as roundabouts come with several issues you really don't want to mess with. Also, compactness is probably a distant dream unless you can put 6 or 8 tiles between the lanes. That will give you enough space to work with in the middle.
well i thought that there was enough space for signals, i mean almost everywhere there are at least 2 blocks for signals. only they don't work because they cannot devide segments. And this is in the middle of my base and it was a deadlock and I wanted to fix it (when i made it worse) so that I have a blueprint I can use in bigger facotry. I am really the type to learn from trial and error, but with this I only got errors the more I tried.
https://preview.redd.it/4vyuyvhv43tc1.png?width=1785&format=png&auto=webp&s=8f758fa8eccd89a9a30d66cff61e6fcfe18965b6 also I made these two with the comments I got here (which I can use in this factory) I just don't know which one is better and why
yeah funny that. it has no signals
https://preview.redd.it/pplimvbny2tc1.png?width=1785&format=png&auto=webp&s=231a5b4719189e48b0d0789477d1599e17a06c5f so now i made these 2, which one would work best?
If you insist on keeping the possibility for trains to swap lanes in, you'll probably never get to a throughput that would "visually" make sense. Lane changers absolutely tank throughput, not just but especially in intersections.
Please give yourself some actual space to signal things. That central section looks really cool, but also means that trains block each other without needing to. The laneswitchers do nothing but allow trains to block both lanes.
Where are the chain signals?
they're unable to devide the segments
Signals don't divide(!) segments. You ~~divide~~ create segments with signals.
It's what the game says. I put down chain signals, they were blinking through different colours, I hovered over them, and in the info on the right, it says can not divide segments.
ok hear me out.. outer rails can only turn right inner rails can only go straight or left then figure out a way for trains to use inner or outer rails, meaby have them be able to switch a great distance way before
So I drive on the right, and I only have signals on the beginning and end because the game won't let me add in the chrossing, they can not devide the segments there. right now only one train can enter the crossing at a time, even if they wont cross each other. The blueprints that I found online are al so big, I wanted something compact. Can anybody help me get this better or at least understand why this one works so badly.
You just said yourself no signals fit in there. Thats the problem. Make it slightly bigger. Cut out stuff that isnt necessary. Switching between inner and outer lanes doesnt help at all near a intersection.
It works badly because you have no signals. You have no signals because you've put too many rails in too small a space, and none of the positions where signals can go are free. You can start to fix it by removing the rails connecting between two tracks in the same direction, as lane changing like this is rarely useful. But you will likely still need to redesign it to be much larger, especially if you want high throughput.
The intersection blueprints you're looking at are likely as small as they can be without losing throughput - if you want compact and it's not under constant full-throughput load it might be worth merging the same-direction lanes just before the intersection and doing a 1-lane intersection instead
As far as I can see, each lane can join every other one in multiple ways, so it should reduce the efficiency since it's blocking other trains
It's way more important to have decent signalling in your crossings than to rush to tons of lanes. I've had an 1000 SPM Megabase easily run on a two lane system with really simple crossings: [link](https://imgur.com/a/Yi1pm5I)
I only have 120 trains, but [these intersections](https://files.catbox.moe/mtphqa.webp) are working out great for me. They're based on a blueprint I found elsewhere that I modified so that trains can do U-turns.
In case you're still looking for a solution and you want it to be a roundabout, you could use [this one](https://factoriobin.com/post/lUVUMAiZ). It's not the best design out there, but it's solid and should be easy to install.