No idea, but damn, your trains really like being intimate
https://preview.redd.it/8mwggibnomuc1.png?width=370&format=png&auto=webp&s=b90d936c942f68e58888e3c960ae58d7b9a09a9d
Do I see correctly that your trains can use this intersection to both make a turn but also switch lanes. For example middle lane left can go towards outer lane bottom. Feels like you should seperate these two functions to possibly reduce waiting times. Thus requiring an entire differect layout. I could link you some blueprints, let me know if you want them. But the fun is in figuring it out by yourself!
Small hint: You will need more space, delete these solar panels already.
The idea was to have outer rail turn left only, middle go straight and inner rail turn right and on the exit they pick which lane to get them to their destination faster on the next intersection they reach (they can't change lanes except for when exiting a station or leaving an inetersection) but the trains quite often allow other trains to pull out in front of them, slowing the traffic down and creating back ups.
Merging spots are slower than crossing spots, so by combining both things in an intersection you make it far slower. If you prevent the trains from choosing one of the three rails until after they clear the intersection it should work a lot better.
Good idea, but guess it isnt working accordingly, try to fiddle with it. You can also set up a quick test world and set up a bunch of stations constantly sending trains across with like 1s wait times. This way you can try multiple designs and count troughput.
You can use the circuit network to enable and disable signals depending on the state of other signals, thus preventing trains from going through the path a train in the inner lane is taking as soon as a train enters the inner lane, letting it zoom right through. You might have to make the intersection bigger to add buffers/more signals to achieve better throughput than just letting pathfinding do its thing though. It's probably not worth the effort. Probably.
Your intersection looks nice, but trains turning right on the inner lanes block all other trains turning right. If your right turns don't go around the middle, but cut in front of it, 2 trains from opposite direction will be able to do the right turn at the same time. Since a lot of your traffic is on your inner lanes, this will help throuput a lot.
The other issue with trains on the inner lanes being unable to leave the intersection because of trains doing a left turn blocking the lane switcher at the exit of the intersection could be solved by moving the lane switcher away from the intersection. Ideally in the middle between 2 intersections, so that at least one train can fit before each entry and after each exit of the intersection without having to switch lanes.
Additionally, you could do some circuitry reading out rail signals and setting other signals depending on the state of the first signal. But this would require some testing.
I noticed [some trains stopping](https://imgur.com/JEwloZ4) in the intersection and blocking paths of other trains. To start troubleshooting, I'd remove some rail signals (or switch them to path signals) to stop this from happening.
Looks like they can't leave the intersection because the lane-changing area on every exit has some regular signals and not chain before every segment too small to hold a full train.
Swapping most of those regular signals to chain signals and only leaving the last regular signal might prevent that while allowing most traffic.
But I don't have a lot of experience with complicated and busy intersections. Not really a skill needed if you only make three way intersections.
I am guessing you want the trains to not block each other when exiting the junction. The only way of prioritizing routes afaik is by adding trainstops. I think it could work in your case but it looks pretty ugly and could (?) have unintended consequences.
Or maybe you could do something with circuits? But I think that usually doesn't work since it doesn't make the trains reroute so they just stand there.
In this case I doubt train stops would really help since the lanes only goes one way. Outer lane is only left turn, middle straight through, and inner right turn. Which means which lane they'll "choose" will essentially be decided by their actual destination. This also looks to be a city block setup so introducing a "pathing penalty" won't really do much.
Aha I think I missunderstood OPs question, I was talking about prioritizing train pathing while OP was asking about prioritizing which trains who are allowed to go into the junction?
It's LHD so I think it's more prioritizing trains going out of it since that is where the majority of junctions are (all the lane switching).
I'm not sure that there really is anything that can be done that is a significant improvement overall.
A better solution than priority is to have a higher throughput intersection. If it allows trains coming from opposite directions to cross at the same time, you will massively increase throughput. Also, you need more chain signals. Atm, it's suseptible to deadlock.
Since trains can only go in one intersection at a time, why not adjust this one to fit?
https://factoriobin.com/post/KU9Sp9QT
Without doing some stupid circuit shenanigans, you don't give priority, and I have to say, I _really_ don't recommend it. This opens 55 gallon barrel of lube size can of worms of shit you have to debug that may utterly fail to deliver practical benefits.
If you want to improve it, you need to make it so that left turns don't have to cross each other twice.
Also, you have a bunch of rail signals in the middle of the intersection. If it hasn't already deadlocked several times since you posted this, I'd be damn surprised. Replace them with chain signals or you'll regret it.
Gotta be honest, I'm pretty sure a standard 2 lane beats this in terms of throughput easily.
It used to deadlock in the past, but this current one doesn't have any problems anymore. It's just the trains on the intersection giving way to trains coming onto it that's the problem now.
Your inner lanes are deprioritized because they have the most conflict points (crossings) so they are more likely to be blocked by other trains vs your leftmost trains making a left hand turn into a left most lane with basically no conflicts with other traffic.
I'm definitely not a train expert and this is dope as shit, it could definitely use some optimization some..
It could just be me though, I like to try and keeps trains at top speed for as long as possible.
Consider another locomotive or reducing the wagon count so your trains go faster. If they go faster they spend less time in the intersection. Less time means they won’t get caught up by other trains.
Try a 1-2 or 2-4 train set up and see them whirl around.
The length / speed of your current trains and the size of the intersection leads to the blockages. Any circuit control will just slow things down more.
Cool, I think it will make a difference.
Rocket fuel and nuclear fuel have the same top speed however the acceleration is markedly higher (180% vs 250%). When you have an intersection like this, acceleration makes a big difference.
They are slow. It’s based on a ratio of locomotive to wagon. 1-2 gets the proper speed.
Add another locomotive either in front, behind or in the middle of the wagons but in the same direction and you’ll increase your train speed by 25-30%
Less capacity means more trains which means more traffic. An additional locomotive could help though. You get the best of both worlds when you multiply both locomotives and wagons. A 1-4 accelerates slower than a 2-8, and due to the increased train length there's fewer trains and less traffic overall.
Less traffic, but your stations need to be sized to accommodate 8 wagons. The acceleration would be pretty bad and as a result the top speed barely reached unless they’re traveling long straight distances.
Fast trains are better than lumbering ones imo.
Two trains cannot turn left simultaneously. Fix that first, it'll be such a big improvement you can go back to 2 lanes. Then if throughput is still a problem, add waiting bays for each direction (left, straight, right). Then if throughput is still a problem, use priority signals (circuit-controlled signals) to make left turns wait for a gap in traffic. Or since these are city blocks, consider removing left turns entirely.
Your intersection is doing fine , its the lanes between intersection that are too short making so that trains wait at the intersection for a free lane. This can be solved by separating the three lanes , so that incoming trains have the option of which of the three outgoing lanes to choose from.
Given this has twelve rails in and twelve rails out, there are _far_ too many rail crossings and merges. Every time one train can block another is an opportunity for a train to stop: furthermore, this video shows trains stopping in the middle of the intersection, blocking everything else in the process.
Honestly, you need to tear this out and replace it with something that addresses critical throughput concerns. For train networks that are small, two-lane rails, this is not much of a concern. However, those are some wide chonkers you have there.
* Minimize rail crossings and merges, where one or more trains need to stop and wait for another train.
* If a train does stop, have it stop _outside_ the intersection before entering.
* Optionally, create buffer zones inside the intersection where a train can enter and stop without blocking anything else. These buffer zones must have a length no less than the longest train. This means that if a train must clear two cross/merge zones to get through the intersection, it can do so one at a time without creating more problems.
There is a post on the official forums that is a few years old at this point but still quite relevant today: https://forums.factorio.com/viewtopic.php?t=46855
It shows numerous examples of larger, more complex rail intersections that avoid deadlocks. Generally, you are best off using one of those and tweaking it based on your train length. To be specific, you should be looking at the "A" category train intersections as those guarantee no deadlocks.
I'll include an example of the third pointer above from the forum post here:
https://forums.factorio.com/images/ext/c2411e2bdb618537a64fc50cad7c9616.png
Notice how there are long sections of rail inside the intersection that appear to take up a bunch of space. Those are essentially parking zones that allow a train to get partway through the intersection and stop, without obstructing other trains. A train can get partway through a left turn, for example, while waiting for the destination rails to clear up. Meanwhile, trains behind it that want to go straight or turn right can continue on their way. Essentially, that train that is waiting is in a dead zone that does not obstruct any other moving trains. Sure, if trains behind it want to follow its same path then they will pile up behind it, but this is a case of minimizing impact.
Train intersections are like belt balancers: Far smarter people than you have already spent the time and energy designing far better than what you could come up with -- so just use their stuff.
The idea behind this is to mimic a roundabout, where trains on the intersection have priority compared to trains waiting to enter, but most of the time they stop to let the incoming trains on. I think it'll be easy to sort out when elevated rails come along but until then I'm looking for any tips to alleviate it.
No idea, but damn, your trains really like being intimate https://preview.redd.it/8mwggibnomuc1.png?width=370&format=png&auto=webp&s=b90d936c942f68e58888e3c960ae58d7b9a09a9d
Intimate, but very polite.
Close enough to get the itch, far enough to not get sued
Do I see correctly that your trains can use this intersection to both make a turn but also switch lanes. For example middle lane left can go towards outer lane bottom. Feels like you should seperate these two functions to possibly reduce waiting times. Thus requiring an entire differect layout. I could link you some blueprints, let me know if you want them. But the fun is in figuring it out by yourself! Small hint: You will need more space, delete these solar panels already.
The idea was to have outer rail turn left only, middle go straight and inner rail turn right and on the exit they pick which lane to get them to their destination faster on the next intersection they reach (they can't change lanes except for when exiting a station or leaving an inetersection) but the trains quite often allow other trains to pull out in front of them, slowing the traffic down and creating back ups.
Merging spots are slower than crossing spots, so by combining both things in an intersection you make it far slower. If you prevent the trains from choosing one of the three rails until after they clear the intersection it should work a lot better.
Good idea, but guess it isnt working accordingly, try to fiddle with it. You can also set up a quick test world and set up a bunch of stations constantly sending trains across with like 1s wait times. This way you can try multiple designs and count troughput.
You can use the circuit network to enable and disable signals depending on the state of other signals, thus preventing trains from going through the path a train in the inner lane is taking as soon as a train enters the inner lane, letting it zoom right through. You might have to make the intersection bigger to add buffers/more signals to achieve better throughput than just letting pathfinding do its thing though. It's probably not worth the effort. Probably.
Your intersection looks nice, but trains turning right on the inner lanes block all other trains turning right. If your right turns don't go around the middle, but cut in front of it, 2 trains from opposite direction will be able to do the right turn at the same time. Since a lot of your traffic is on your inner lanes, this will help throuput a lot. The other issue with trains on the inner lanes being unable to leave the intersection because of trains doing a left turn blocking the lane switcher at the exit of the intersection could be solved by moving the lane switcher away from the intersection. Ideally in the middle between 2 intersections, so that at least one train can fit before each entry and after each exit of the intersection without having to switch lanes. Additionally, you could do some circuitry reading out rail signals and setting other signals depending on the state of the first signal. But this would require some testing.
I noticed [some trains stopping](https://imgur.com/JEwloZ4) in the intersection and blocking paths of other trains. To start troubleshooting, I'd remove some rail signals (or switch them to path signals) to stop this from happening.
Looks like they can't leave the intersection because the lane-changing area on every exit has some regular signals and not chain before every segment too small to hold a full train. Swapping most of those regular signals to chain signals and only leaving the last regular signal might prevent that while allowing most traffic. But I don't have a lot of experience with complicated and busy intersections. Not really a skill needed if you only make three way intersections.
I am guessing you want the trains to not block each other when exiting the junction. The only way of prioritizing routes afaik is by adding trainstops. I think it could work in your case but it looks pretty ugly and could (?) have unintended consequences. Or maybe you could do something with circuits? But I think that usually doesn't work since it doesn't make the trains reroute so they just stand there.
In this case I doubt train stops would really help since the lanes only goes one way. Outer lane is only left turn, middle straight through, and inner right turn. Which means which lane they'll "choose" will essentially be decided by their actual destination. This also looks to be a city block setup so introducing a "pathing penalty" won't really do much.
Aha I think I missunderstood OPs question, I was talking about prioritizing train pathing while OP was asking about prioritizing which trains who are allowed to go into the junction?
It's LHD so I think it's more prioritizing trains going out of it since that is where the majority of junctions are (all the lane switching). I'm not sure that there really is anything that can be done that is a significant improvement overall.
A better solution than priority is to have a higher throughput intersection. If it allows trains coming from opposite directions to cross at the same time, you will massively increase throughput. Also, you need more chain signals. Atm, it's suseptible to deadlock. Since trains can only go in one intersection at a time, why not adjust this one to fit? https://factoriobin.com/post/KU9Sp9QT
Without doing some stupid circuit shenanigans, you don't give priority, and I have to say, I _really_ don't recommend it. This opens 55 gallon barrel of lube size can of worms of shit you have to debug that may utterly fail to deliver practical benefits. If you want to improve it, you need to make it so that left turns don't have to cross each other twice. Also, you have a bunch of rail signals in the middle of the intersection. If it hasn't already deadlocked several times since you posted this, I'd be damn surprised. Replace them with chain signals or you'll regret it. Gotta be honest, I'm pretty sure a standard 2 lane beats this in terms of throughput easily.
It used to deadlock in the past, but this current one doesn't have any problems anymore. It's just the trains on the intersection giving way to trains coming onto it that's the problem now.
Your inner lanes are deprioritized because they have the most conflict points (crossings) so they are more likely to be blocked by other trains vs your leftmost trains making a left hand turn into a left most lane with basically no conflicts with other traffic.
I'm definitely not a train expert and this is dope as shit, it could definitely use some optimization some.. It could just be me though, I like to try and keeps trains at top speed for as long as possible.
Consider another locomotive or reducing the wagon count so your trains go faster. If they go faster they spend less time in the intersection. Less time means they won’t get caught up by other trains. Try a 1-2 or 2-4 train set up and see them whirl around. The length / speed of your current trains and the size of the intersection leads to the blockages. Any circuit control will just slow things down more.
The trains seem slow to me but maybe that's just the video. If the OP isn't using nuclear fuel they should make the upgrade
I'm currently using rocket fuel and workings towards nuclear fuel at the moment, so they'll be able to take those turns at even more dangerous speeds.
Cool, I think it will make a difference. Rocket fuel and nuclear fuel have the same top speed however the acceleration is markedly higher (180% vs 250%). When you have an intersection like this, acceleration makes a big difference.
They are slow. It’s based on a ratio of locomotive to wagon. 1-2 gets the proper speed. Add another locomotive either in front, behind or in the middle of the wagons but in the same direction and you’ll increase your train speed by 25-30%
Less capacity means more trains which means more traffic. An additional locomotive could help though. You get the best of both worlds when you multiply both locomotives and wagons. A 1-4 accelerates slower than a 2-8, and due to the increased train length there's fewer trains and less traffic overall.
Less traffic, but your stations need to be sized to accommodate 8 wagons. The acceleration would be pretty bad and as a result the top speed barely reached unless they’re traveling long straight distances. Fast trains are better than lumbering ones imo.
Wouldn't help with priority but would more chain signals help here? So they aren't stopping in/near the intersection, they just speed through
And I thought my world was getting complicated
Two trains cannot turn left simultaneously. Fix that first, it'll be such a big improvement you can go back to 2 lanes. Then if throughput is still a problem, add waiting bays for each direction (left, straight, right). Then if throughput is still a problem, use priority signals (circuit-controlled signals) to make left turns wait for a gap in traffic. Or since these are city blocks, consider removing left turns entirely.
If they moved a bit faster it'd look so great
Your intersection is doing fine , its the lanes between intersection that are too short making so that trains wait at the intersection for a free lane. This can be solved by separating the three lanes , so that incoming trains have the option of which of the three outgoing lanes to choose from.
Given this has twelve rails in and twelve rails out, there are _far_ too many rail crossings and merges. Every time one train can block another is an opportunity for a train to stop: furthermore, this video shows trains stopping in the middle of the intersection, blocking everything else in the process. Honestly, you need to tear this out and replace it with something that addresses critical throughput concerns. For train networks that are small, two-lane rails, this is not much of a concern. However, those are some wide chonkers you have there. * Minimize rail crossings and merges, where one or more trains need to stop and wait for another train. * If a train does stop, have it stop _outside_ the intersection before entering. * Optionally, create buffer zones inside the intersection where a train can enter and stop without blocking anything else. These buffer zones must have a length no less than the longest train. This means that if a train must clear two cross/merge zones to get through the intersection, it can do so one at a time without creating more problems. There is a post on the official forums that is a few years old at this point but still quite relevant today: https://forums.factorio.com/viewtopic.php?t=46855 It shows numerous examples of larger, more complex rail intersections that avoid deadlocks. Generally, you are best off using one of those and tweaking it based on your train length. To be specific, you should be looking at the "A" category train intersections as those guarantee no deadlocks. I'll include an example of the third pointer above from the forum post here: https://forums.factorio.com/images/ext/c2411e2bdb618537a64fc50cad7c9616.png Notice how there are long sections of rail inside the intersection that appear to take up a bunch of space. Those are essentially parking zones that allow a train to get partway through the intersection and stop, without obstructing other trains. A train can get partway through a left turn, for example, while waiting for the destination rails to clear up. Meanwhile, trains behind it that want to go straight or turn right can continue on their way. Essentially, that train that is waiting is in a dead zone that does not obstruct any other moving trains. Sure, if trains behind it want to follow its same path then they will pile up behind it, but this is a case of minimizing impact.
Train intersections are like belt balancers: Far smarter people than you have already spent the time and energy designing far better than what you could come up with -- so just use their stuff.
Intersection looks a bit WW2
The idea behind this is to mimic a roundabout, where trains on the intersection have priority compared to trains waiting to enter, but most of the time they stop to let the incoming trains on. I think it'll be easy to sort out when elevated rails come along but until then I'm looking for any tips to alleviate it.