Train Pathing Question

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dog80
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Train Pathing Question

Post by dog80 » Thu Dec 28, 2017 6:23 pm

Why does the train not take the yellow marked waiting area? I know how to work around that, but i stumbled over this problem now several times and it forces me to build the train network in a specific way.

(green is the way the train will take when there is green light)
r5g5re61g5r.jpg
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- the 2 red marked signals can be removed that would fix the issue, though it destroys the way i wanted to setup the network, because i'd like to have other trains pass this rail in both directions, which is not implemented here.

- Also swapping the drive-through and waiting-bay would be a solution (image2), though again it forces me to build it in a specific way.
r5g5re61g5r-1.jpg
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in reality trains would ofcourse take the waiting bay because the distance to the left could be much larger. I suspect that this advanced path finding would very complex etc. so taking the solution of the direct way is the only one...

nvm this is just for my personal understanding, thx for any help.

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Re: Train Pathing Question

Post by orzelek » Thu Dec 28, 2017 6:51 pm

I'm not 100% sure but I think that train choses path that seems shorter regardless of signal state on that path.
If you move the siding to other side of main rail it will have same length as main track and should be used more often since pathing cost will be same as main line.

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Re: Train Pathing Question

Post by dog80 » Thu Dec 28, 2017 6:53 pm

orzelek wrote:I'm not 100% sure but I think that train choses path that seems shorter regardless of signal state on that path.
If you move the siding to other side of main rail it will have same length as main track and should be used more often since pathing cost will be same as main line.
yes that is correct - but again maybe at a certain point there is no possibility to move it on the other side

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Re: Train Pathing Question

Post by aaargha » Fri Dec 29, 2017 3:13 pm

This is caused by the pathfinder not looking whether a signal is red or not - except for circuits - but whether or not there is a train in the block. As there is no train in either block the only thing the pathfinder has to differentiate with is how long the paths are. Changing how that works seems like it would not be that easy to me at least, especially handling chain signals correctly and efficiently.

Another workaround for this could be to make the siding the only entrance to the train station, this should only need very little space.

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Re: Train Pathing Question

Post by pleegwat » Fri Dec 29, 2017 4:50 pm

I could see giving some penalty to paths through a two-way signal.

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Re: Train Pathing Question

Post by Jap2.0 » Sat Dec 30, 2017 4:27 pm

I think that part of it could be that paths are calculated when the train departs, and it rarely recalcultes, although in that case I would think that it would choose the correct path. Also, you're on 0.16, right?
aaargha wrote:This is caused by the pathfinder not looking whether a signal is red or not - except for circuits - but whether or not there is a train in the block. As there is no train in either block the only thing the pathfinder has to differentiate with is how long the paths are. Changing how that works seems like it would not be that easy to me at least, especially handling chain signals correctly and efficiently.

Another workaround for this could be to make the siding the only entrance to the train station, this should only need very little space.
Really? I thought that penalties were given with 2(block length) for red signals, and that circuit-controlled signals just gave a constant penalty of 1000?
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Re: Train Pathing Question

Post by Jap2.0 » Sat Dec 30, 2017 4:36 pm

Ah, this is relavent. I'm not entirely sure why this is happenning, though.
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Re: Train Pathing Question

Post by dog80 » Sun Dec 31, 2017 5:04 pm

pleegwat wrote:I could see giving some penalty to paths through a two-way signal.
Sounds valid to me

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Re: Train Pathing Question

Post by cbhj1 » Sun Dec 31, 2017 5:30 pm

not sure it matters to the discussion, but the rail signal going into the waiting bay is red without a train in the block

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Re: Train Pathing Question

Post by aaargha » Mon Jan 01, 2018 10:04 am

cbhj1 wrote:not sure it matters to the discussion, but the rail signal going into the waiting bay is red without a train in the block
Which signal are you referring to, as far as I can tell they all look like they're in the correct state?

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Re: Train Pathing Question

Post by cbhj1 » Mon Jan 01, 2018 2:17 pm

in the second picture, the entrance to the empty waiting bay

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Re: Train Pathing Question

Post by Jap2.0 » Mon Jan 01, 2018 7:56 pm

cbhj1 wrote:in the second picture, the entrance to the empty waiting bay
Nope - it's a chain signal.
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Re: Train Pathing Question

Post by cbhj1 » Mon Jan 01, 2018 9:29 pm

so it is, my mistake

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Re: Train Pathing Question

Post by Triaxx2 » Tue Jan 02, 2018 4:33 am

I'm not seeing a second signal for the interior signals on the upper side to be chained off of. They're connecting to the signal on the far end past the incoming train. Which is why they're red, so the train is going through because it's already in the block.

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Re: Train Pathing Question

Post by dog80 » Thu Mar 15, 2018 11:50 am

Triaxx2 wrote:I'm not seeing a second signal for the interior signals on the upper side to be chained off of. They're connecting to the signal on the far end past the incoming train. Which is why they're red, so the train is going through because it's already in the block.
the station

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