After some additional testing I've thoroughly convinced myself that you are right and this is not a property of buffered intersections at all, but rather it's a consequence of how trains path in factorio more generally. That means this problem, while real, is off topic for this thread. Therefore, I'll take some of your suggestions into account and develop solutions elsewhere. Sorry for the detour, and thanks for everything y'all have contributed here.
Testbench v4.2.1, Factorio v1.1.46
3-Way, 2-Lane, Unbuffered, spacing is 4 everywhere. Currently better than the only thing listed on that section.
R452736.png
This is really the way, i was wondering why posted 3-ways are still unoptimized at the center. When 3 rails form a triangle, only 1 train can pass at the time. It doesn't add any benefits putting chain signals in it, but instead shrink the rails to form a "star". It makes chain-rail pairs closer together and lets trains clear the crossing faster.
Re: 3 and 4 way intersections
Posted: Fri May 27, 2022 7:09 pm
by Hovedgade
I am back with more intersections.
I took some inspiration from my blitz roundabout but then i rotated it 45°and added frontend buffers. The first design does not use parallel buffers for the same direction and it scored slightly better than Windmill MK2. The second design has more parallel buffers than absolutely necessary which made it score about the same as Hurricane 1.2. The intersections does look somewhat similar to mosaic tiles and hence the reasoning behind the names.
i was wondering why posted 3-ways are still unoptimized at the center.
They were probably made to be converted into a symmetrical cross. So they were "optimized" for ease of use. I don't believe the score is much different anyhow which is why I personally didn't change it but I could optimize them for tpm after I get the parts for my computer since it died...
I am back with more intersections.
I took some inspiration from my blitz roundabout but then i rotated it 45°and added frontend buffers. The first design does not use parallel buffers for the same direction and it scored slightly better than Windmill MK2. The second design has more parallel buffers than absolutely necessary which made it score about the same as Hurricane 1.2. The intersections does look somewhat similar to mosaic tiles and hence the reasoning behind the names.
There was an accident while designing the intersections which made this beautiful pattern that I'd like to share.
Mosaic ball.JPG
Great as always Hovedgade, I like those intersections. I tested them and got the same score as you. Thanks again for the formula, its in use with the TPM adjuster.
Re: 3 and 4 way intersections
Posted: Wed Jun 01, 2022 2:05 am
by farcast
Abstract 4-lane 3-way
Abstract.png (272.07 KiB) Viewed 4738 times
Abstract in action.gif (432.77 KiB) Viewed 4738 times
I've done it! I've made a working junction out of scribbles!
Using Throughput tester v5.0.7
RHT/LHT (When did D become T? What does T stand for?)
Score: 112/110
Set1: 115/114
Set2: 110/107
I couldn't get it to be perfectly stable like with clockwork, so the score you get will be rather sensitive to signal spacing on the input lines, but the given score is what you should get if you don't bother with that and just rely on the provided entrance buffers. This junction was designed for a signal spacing of 60-ish tiles, or roughly 8 to 9 cars long.
Abstract construction guide
Abstract Construction Guide.png (320.37 KiB) Viewed 4738 times
Resizing it is easier than it looks because it's actually made out of equilateral triangles, so you just need to resize four different connecting segments. Aside from that, there are the three places that cross in parallel instead of merge (red), three places that merge instead of cross (green), and three places where the outer lane splits and merges into an exit (blue).
2-coloring
2-coloring.png (186.63 KiB) Viewed 4738 times
I thought of using constant combinators to find a good 2-coloring first, then building that 2-coloring with rails. As you can guess, my attempts at step 2 were rather unsuccessful until I realized the whole thing was made of triangles.
Continuing my investigations into this synchronous behavior, I made a graph on desmos that calculates the expected TPM per lane for synchronous crossings across different buffer lengths, for a given train design and crossing length in meters. It includes the special cases where the train hits max speed, and when it's max speed from the start. The train stats used were found through a bit of research and a lot of experimentation. The units are all SI units.
-Thrust, (b)raking force, and friction are in Newtons.
-(d) is braking distance.
-Drag is in Newtons per (meters per second), or Newton-seconds per meter.
-t0 : the back of the train is against the rail signal behind it with the stop point at the chain signal in front.
-t1a: the time it takes for the stop point to reach the chain signal of the next crossing.
-t2a: the time it takes for the brakes to slow the train back to v0.
-switches to tb if the train would hit max speed before the stop point reaches the next crossing
-t1b: the time needed to reach max speed from v0.
-t2b: the time it takes after t1b for the train to be fully within the next buffer.
-t3b: the time it takes for the brakes to slow the train back to v0.
I'd love to say I know exactly how the formulas for distance/velocity/acceleration over time come about, but the truth is I found the velocity formula while experimenting with regressions in desmos and guessing at where the variables should go.
So, did this graph help me understand synchronous crossings?
... not really, no. I thought maybe using the buffer length with the most throughput would translate to being the most stable, but building abstract like that was just as unstable as the one used here. At this point I'm kind of out of ideas as to how to figure out what makes it stable.
Edit: Updated scores and added a rail signal to the LHT version.
[
RHT/LHT (When did D become T? What does T stand for?)
Score: 109/111
Set1: 115/114
Set2: 104/108
Hey Farcast, what a cool intersection! I'll test it later. RHD is a term describing where the wheel is placed in a car so cars with RHD drives on the left side of the road. Since our use of RHD/LHD is completely wrong and opposite to real life, we decided to use a better term which is Right Hand Traffic and Left Hand Traffic. Which are precise and correct terms.
In my language we say translated rightdriving/leftdriving where rightdriving is driving on the right.
But in English right hand drive means the steering wheel is on the right side of the car. And cars with the steering wheel on the right side are made for driving on the left side of the road.
Source: https://dictionary.cambridge.org/dictio ... hand-drive
In my language we say translated rightdriving/leftdriving where rightdriving is driving on the right.
But in English right hand drive means the steering wheel is on the right side of the car. And cars with the steering wheel on the right side are made for driving on the left side of the road.
Source: https://dictionary.cambridge.org/dictio ... hand-drive
Erm, ok. I'm a native English speaker and I've always understood RHD/LHD to be the side of the road you're driving on, not the steering wheel. Dunno, maybe I learned differently? I don't have anyone to compare with.
In my language we say translated rightdriving/leftdriving where rightdriving is driving on the right.
But in English right hand drive means the steering wheel is on the right side of the car. And cars with the steering wheel on the right side are made for driving on the left side of the road.
Source: https://dictionary.cambridge.org/dictio ... hand-drive
Erm, ok. I'm a native English speaker and I've always understood RHD/LHD to be the side of the road you're driving on, not the steering wheel. Dunno, maybe I learned differently? I don't have anyone to compare with.
On the old 4 way forum aaargha used RHD/LHD wrong and I think many learned it from there. I think especially us that are non native English speakers didn't question it. I didn't question it before I saw multiple times in the Factorio discord chat that we are using RHD/LHD wrong.
On the old 4 way forum aaargha used RHD/LHD wrong and I think many learned it from there. I think especially us that are non native English speakers didn't question it. I didn't question it before I saw multiple times in the Factorio discord chat that we are using RHD/LHD wrong.
Huh, ok. I just got through doing some googling, too, and yeah, you're right. :/ Will probably take me a while to unlearn that....
On the old 4 way forum aaargha used RHD/LHD wrong and I think many learned it from there. I think especially us that are non native English speakers didn't question it. I didn't question it before I saw multiple times in the Factorio discord chat that we are using RHD/LHD wrong.
Huh, ok. I just got through doing some googling, too, and yeah, you're right. :/ Will probably take me a while to unlearn that....
I think the terms can live side by side. Switching LHD with RHD would make chaos, so going to RHT and LHT is easier since it's only changing a letter
On the old 4 way forum aaargha used RHD/LHD wrong and I think many learned it from there. I think especially us that are non native English speakers didn't question it. I didn't question it before I saw multiple times in the Factorio discord chat that we are using RHD/LHD wrong.
Huh, ok. I just got through doing some googling, too, and yeah, you're right. :/ Will probably take me a while to unlearn that....
I think the terms can live side by side. Switching LHD with RHD would make chaos, so going to RHT and LHT is easier since it's only changing a letter
Agreed, I get that. I'm just saying it's going to take me a while to unlearn (or relearn) what LHD and RHD really mean.
On the old 4 way forum aaargha used RHD/LHD wrong and I think many learned it from there. I think especially us that are non native English speakers didn't question it. I didn't question it before I saw multiple times in the Factorio discord chat that we are using RHD/LHD wrong.
Huh, ok. I just got through doing some googling, too, and yeah, you're right. :/ Will probably take me a while to unlearn that....
I think the terms can live side by side. Switching LHD with RHD would make chaos, so going to RHT and LHT is easier since it's only changing a letter
Agreed, I get that. I'm just saying it's going to take me a while to unlearn (or relearn) what LHD and RHD really mean.
I don't think you need to, since people will use RHD for RHT in Factorio for years to come. I'm pretty sure no one will call "RHT" for LHD.
Erm, ok. I'm a native English speaker and I've always understood RHD/LHD to be the side of the road you're driving on, not the steering wheel. Dunno, maybe I learned differently? I don't have anyone to compare with.
I am also a native speaker but don't recall using RHD before Factorio. Talking about which side of the road we drive on wasn't a common subject for me. A user on discord had been suggesting RHT/LHT for years at that point so Hans brought it up. Hans, Kano, and I had a very long conversation about this and after reviewing the evidence, switching seemed simple and persuasive.
Erm, ok. I'm a native English speaker and I've always understood RHD/LHD to be the side of the road you're driving on, not the steering wheel. Dunno, maybe I learned differently? I don't have anyone to compare with.
I am also a native speaker but don't recall using RHD before Factorio. Talking about which side of the road we drive on wasn't a common subject for me. A user on discord had been suggesting RHT/LHT for years at that point so Hans brought it up. Hans, Kano, and I had a very long conversation about this and after reviewing the evidence, switching seemed simple and persuasive.
I've used RHD = RHT = people drive on the right side of the road, exclusively in the context of factorio, without ever knowing i was doing a mistake and i've used it a lot but i am convinced too now.
Abstract in action.gif
I've done it! I've made a working junction out of scribbles!
Nice man, I have put it on the page, got the same scores as you.
Tested with 5.1.1
Re: 3 and 4 way intersections
Posted: Wed Jun 08, 2022 7:55 pm
by hansjoachim
The goal was to make the highest throughput 4-way unbuffered intersection. This intersection now holds the highscore for 4-way unbuffered intersections.
It looks larger than the others, but when Including the safe outputs it really isn't.
set 1: 52
Set 2: 41
Set 3 46
Average: 47 https://factoriobin.com/post/-UFOZDli
Re: 3 and 4 way intersections
Posted: Wed Jul 06, 2022 1:53 am
by ElderAxe
I have tested a slightly modified version of my "Almost squareabout OCD" blueprint with testbench 5.1.1. It would be nice if you update the post with the new numbers. Also, Darkelder is my previous nickname. It should be ElderAxe as well.
almost-squareabout-ocd.png (2.08 MiB) Viewed 6430 times
but i am convinced too now.