4-way intersections: Throughput and deadlocks [image heavy]

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hansjoachim
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Re: DDI intersection

Post by hansjoachim » Fri Nov 02, 2018 4:59 pm

lululu wrote:
Fri Nov 02, 2018 3:40 pm
I wonder why nobody submitted sth like this already
Its throughput would be lower than a normal one block intersection because north-south and south-north intersect, and also because right turns are too close to the intersection.

set 1 33 trains per min
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Updated version of aaarghas intersection testbench. viewtopic.php?f=194&t=46855&p=383830#p383830
My Highscore intersections: https://pastebin.com/dGsJT71Z
My 3 to 1 train merger https://pastebin.com/AcLHXcwd

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Re: DDI intersection

Post by mrvn » Mon Nov 05, 2018 10:58 am

lululu wrote:
Fri Nov 02, 2018 3:40 pm
I wonder why nobody submitted sth like this already

ddi.PNG
Trains going north block trains going south so that should slow things down.

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by mahury » Tue Nov 06, 2018 7:37 am

About roundabout.
I gamed a lot with celled railroad system. I looked for a simlpe intersection with no crossing, only junctions.
I find no other intersection allows me to make to make turning back.
Roundabout with additional turning rigth will be not so compact.
Firstly I placed safe roundabout. but it was not good. 2 trains can`t cross it directly same time.
After it I placed roundabout with chain-signal inside. It was better but some time it maked deadlocks.
I tried to fix it placing chain signal everywere or only enter/exit. it was better but also not good.
Deadlocks didn`t appeared after I placed in intersection only chain signals and on rail to intersection and afer intersection rail-signal.
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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by hansjoachim » Tue Nov 06, 2018 8:52 am

mahury wrote:
Tue Nov 06, 2018 7:37 am
About roundabout.
I gamed a lot with celled railroad system. I looked for a simlpe intersection with no crossing, only junctions.
I find no other intersection allows me to make to make turning back.
Roundabout with additional turning rigth will be not so compact.
Firstly I placed safe roundabout. but it was not good. 2 trains can`t cross it directly same time.
After it I placed roundabout with chain-signal inside. It was better but some time it maked deadlocks.
I tried to fix it placing chain signal everywere or only enter/exit. it was better but also not good.
Deadlocks didn`t appeared after I placed in intersection only chain signals and on rail to intersection and afer intersection rail-signal.
Ok, so what is the problem?
Updated version of aaarghas intersection testbench. viewtopic.php?f=194&t=46855&p=383830#p383830
My Highscore intersections: https://pastebin.com/dGsJT71Z
My 3 to 1 train merger https://pastebin.com/AcLHXcwd

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by Aeternus » Tue Nov 06, 2018 10:12 am

I'm not a fan of roundabouts... there's a secondary problem with them, if a train changes direction twice while on the roundabout (rare but it happens) the roundabout MUST be able to fit the max length of the train on the system. I found out the hard way that my own rounds were too small to fit the 4engine, 12wagon configuration haulers I ran with. Crash and stall (since a train that loses a wagon automatically switches to manual).

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by mahury » Tue Nov 06, 2018 11:21 am

I have 1-2 trains. I do not understand how to make compact sorter for 2-4. Make more trains is easier way

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by mahury » Tue Nov 06, 2018 11:23 am

hansjoachim wrote:
Tue Nov 06, 2018 8:52 am
mahury wrote:
Tue Nov 06, 2018 7:37 am
About roundabout.
I gamed a lot with celled railroad system. I looked for a simlpe intersection with no crossing, only junctions.
I find no other intersection allows me to make to make turning back.
Roundabout with additional turning rigth will be not so compact.
Firstly I placed safe roundabout. but it was not good. 2 trains can`t cross it directly same time.
After it I placed roundabout with chain-signal inside. It was better but some time it maked deadlocks.
I tried to fix it placing chain signal everywere or only enter/exit. it was better but also not good.
Deadlocks didn`t appeared after I placed in intersection only chain signals and on rail to intersection and afer intersection rail-signal.
Ok, so what is the problem?
how to measure Throughput ?)

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by zOldBulldog » Tue Nov 06, 2018 11:54 am

mahury wrote:
Tue Nov 06, 2018 11:23 am
hansjoachim wrote:
Tue Nov 06, 2018 8:52 am
mahury wrote:
Tue Nov 06, 2018 7:37 am
About roundabout.
I gamed a lot with celled railroad system. I looked for a simlpe intersection with no crossing, only junctions.
I find no other intersection allows me to make to make turning back.
Roundabout with additional turning rigth will be not so compact.
Firstly I placed safe roundabout. but it was not good. 2 trains can`t cross it directly same time.
After it I placed roundabout with chain-signal inside. It was better but some time it maked deadlocks.
I tried to fix it placing chain signal everywere or only enter/exit. it was better but also not good.
Deadlocks didn`t appeared after I placed in intersection only chain signals and on rail to intersection and afer intersection rail-signal.
Ok, so what is the problem?
how to measure Throughput ?)
Read some posts back. Hansjoachim posted an updated zip with an improved testing framework and pretty clear instructions. Or go back to the original post of the thread for the original framework.

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by mahury » Tue Nov 06, 2018 12:11 pm

thanks

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by hansjoachim » Tue Nov 06, 2018 9:44 pm

mahury wrote:
Tue Nov 06, 2018 11:21 am
I have 1-2 trains. I do not understand how to make compact sorter for 2-4. Make more trains is easier way
If you want to test the throughput with 1-2 trains you would have to either use a profile that isn't used yet, or change the trains with profile 1.

To do that, for RHD, find the station with P1, where a train goes to west 1/north 1/south 1/east 1, change that train to be the length you want and do the same four times, once for each area.
Updated version of aaarghas intersection testbench. viewtopic.php?f=194&t=46855&p=383830#p383830
My Highscore intersections: https://pastebin.com/dGsJT71Z
My 3 to 1 train merger https://pastebin.com/AcLHXcwd

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Re: DDI intersection

Post by lululu » Sun Nov 11, 2018 6:10 pm

hansjoachim wrote:
Fri Nov 02, 2018 4:59 pm
lululu wrote:
Fri Nov 02, 2018 3:40 pm
I wonder why nobody submitted sth like this already
Its throughput would be lower than a normal one block intersection because north-south and south-north intersect, and also because right turns are too close to the intersection.

set 1 33 trains per min
if going north to south has priority then you should rotate it, i made it if for example your furnace setup is east and you dont seperate between iron and copper melting and you have iron north and copper south. they will never go north to south and can easily turn east and the ones already coming from west can go through without changing track and i even think trains from west have priority.

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by Aquilo » Wed Nov 14, 2018 9:37 am

My modification of Switching Christmas.
Reduced size (external paths).
Added rule (1 to 8, from any incoming path to any exit), the possibility of a circular reversal.
The possibility of parallel turning of two trains along two parallel tracks was lost. (for the sake of compactness, I need to embed it in a cellular base).

Compact Switching Christmas
BluePrint
Image
Last edited by Aquilo on Wed Nov 14, 2018 1:27 pm, edited 1 time in total.

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by hansjoachim » Wed Nov 14, 2018 10:14 am

I'm not on my computer do you have a screenshot?
Updated version of aaarghas intersection testbench. viewtopic.php?f=194&t=46855&p=383830#p383830
My Highscore intersections: https://pastebin.com/dGsJT71Z
My 3 to 1 train merger https://pastebin.com/AcLHXcwd

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by Aquilo » Wed Nov 14, 2018 1:33 pm

Added screen.

Here is a non-compact version, without a ring.
It differs from the original by additional connections (1 to 6, all except the reversal) and by the possibility of turning to any output line (in the original it is impossible to rebuild at the junction and from the central lane it is impossible to get to the outermost one)
AddSwitching christmas
Image
BluePrint

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by hansjoachim » Wed Nov 14, 2018 11:44 pm

If you want a more compact rail system just make a 2 lane system instead of a 4 lane systen. If you go to a 2 lane system you don't need to worry about lane switching.
The modification you did just made that intersection worse and barely more compact. You should do U turns outside of 4 or 3 way intersections so that you don't butcher throughput.
Seperate U turns doesn't take much space, espassicaly in a 2 lane system
Updated version of aaarghas intersection testbench. viewtopic.php?f=194&t=46855&p=383830#p383830
My Highscore intersections: https://pastebin.com/dGsJT71Z
My 3 to 1 train merger https://pastebin.com/AcLHXcwd

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by immortal_sniper1 » Sat Nov 17, 2018 3:42 pm

some interesting ideas from the last 2 pages gave me some ideas too work in progress atm

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by mrvn » Mon Nov 19, 2018 9:31 am

mahury wrote:
Tue Nov 06, 2018 7:37 am
About roundabout.
I gamed a lot with celled railroad system. I looked for a simlpe intersection with no crossing, only junctions.
I find no other intersection allows me to make to make turning back.
Roundabout with additional turning rigth will be not so compact.
Firstly I placed safe roundabout. but it was not good. 2 trains can`t cross it directly same time.
After it I placed roundabout with chain-signal inside. It was better but some time it maked deadlocks.
I tried to fix it placing chain signal everywere or only enter/exit. it was better but also not good.
Deadlocks didn`t appeared after I placed in intersection only chain signals and on rail to intersection and afer intersection rail-signal.
You forgot the simple rule for signals:

After every signal there must be enough space for a full train before the next signal or chain signal. With your train stops right after the roundabout there wasn't space for a full train so they couldn't leave the roundabout. That then quickly leads to deadlocks.


But aside from that you still get problems. A train can reroute while inside the roundabout and end up taking a 450° turn. If it's long enough, like a LLCCCCCCCC train, it will crash into itself.

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by Tallinu » Tue Nov 27, 2018 7:00 am

During a random google search today I just spotted a comment someone made on reddit many months ago regarding my MultiCross junction designs, and I thought they had a really good point!
(I am unreasonably peeved that you have to take the second turn at an intersection in order to go straight through.)
I never really considered manual train driving at all when designing these things. I always just tell the train where to go and let it take me there, to make sure I don't crash into other trains waiting at signals along the way! ;)

But I've realized it's fairly straightforward to adjust the entrance track-split so that a manual driver going straight would, you know, actually go straight. All it will take is adding a bit of a swerve prior to the split so that holding left or right turns the train out of the "go straight" lane instead of requiring "press left at just the right moment" to turn out of the "turn right" lane without doing it too early and accidentally making a left turn, or too late and making a right turn. That really would be a pain to do correctly!

I'm planning to add that to the next revision, now that I'm aware of it.

---

Done. And now it's 6 AM. Oh well. (The old blueprint book strings are still there if anyone prefers them.)

I also added 12 and 16 car length blueprint books with the basic MultiCross design, so all even lengths from 6 to 16 are now represented (as usual, in both LHD and RHD). And I tossed in a few other blueprint strings I had laying around while I was at it, for the buffered lane changer and T junctions.

The location is the same: Updated MultiCross Version 1.1 Blueprint Strings Etc

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by jaywalkerr » Mon Dec 03, 2018 7:46 pm

I have been looking for a 2-lane 4-way with roundabout that is compact, and made one based on the blueprint book I've been using for a while that I found here.

I could not figure out how to test it with the roundabout, only straight, left and right. I have been skimming through the ones that are posted here, but could not see the same design. I might ofc be half blind, as I'm looking for something that is exactly the same..


Here is the design:
Image

Here is the BP:

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Re: 4-way intersections: Throughput and deadlocks [image heavy]

Post by Tallinu » Mon Dec 03, 2018 8:41 pm

If you mean you want to see a train make a U-turn (the only path which actually appears to require using the roundabout on your design), none of the trains are by default set up to attempt such a path. You can add it yourself to the template trains at the spawners in each direction, but best to do so as a new profile (build a train on one of the currently empty template tracks, then copy the settings from the first train and add the fourth destination).

If you're asking why the test trains aren't driving on the roundabout when making left or right turns or going straight, it's because your junction provides shorter, more direct paths for all of those maneuvers, which the trains will always prefer. Only a U-turn would be required to use the roundabout.

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