Pre-signal is green?

[wizeman]

Check out this situation.

I was trying to prevent the goods-carrying trains from monopolizing all the station entrances. (don't mind the design, it isn't complete. But if anyone knows a good design to prevent this, then I am open to suggestions. )

Anyway, I think the marked entry pre-signal should be red instead of green, don't you think? There's a line crossing with other exit pre-signals which are green, but the train near that signal can't go to the other line, so it shouldn't interfere..

If it's already marked as bug, then I'm sorry . If it isn't, then I would be happy to submit a bug report to sourceforge. If it's a feature, then someone should explain it to me

BTW, using version 0.3.2.1 in linux.

[Lilman424]

I'm guessing that the presignals don't see if there's an actual connection, just a rail.....but I don't know how to fix it, with the exception of a redesign

[ChrisCF]

Try fiddling the land a bit and use a bridge instead.

[wizeman]

I was trying to make the wood trains able to use any station entrance, including those 3. It would be nice if the signals worked correctly.. oh well

[dominik81]

On a junction like that you'll need a signal anyway. Otherwise you'd have trains crashing.

[habell]

Check out this situation.

I was trying to prevent the goods-carrying trains from monopolizing all the station entrances. (don't mind the design, it isn't complete. But if anyone knows a good design to prevent this, then I am open to suggestions. )

Anyway, I think the marked entry pre-signal should be red instead of green, don't you think? There's a line crossing with other exit pre-signals which are green, but the train near that signal can't go to the other line, so it shouldn't interfere..

If it's already marked as bug, then I'm sorry . If it isn't, then I would be happy to submit a bug report to sourceforge. If it's a feature, then someone should explain it to me

BTW, using version 0.3.2.1 in linux.

Ofcourse it's green, platform 1 and 2 from the top are free.

Change the two signals on platform 1 and 2 to a normal two-way signal and the antrance for the other trains (not de goods) to a normal one-way signal.

Thisway the signal you want to be red, will be red when platform 3 through 5 are full.

[Darkvater]

I see no problem either. 2 tracks are free, so signal is green. What's wrong with that?

[Korenn]

another way to split the tracks but still allow the trains to use all platforms is like this:

[wizeman]

I don't think any of you really understand what I wanted.

habell and Darkvater, the problem is that the signal is green when the top 2 platforms are free, but there is no way to go to those platforms.. no train can turn in a crossing like that, so the signal shouldn't account for those platforms. Really! Watch closely.

Although habell's sugestion did make the signal work correctly, it doesn't fix the underlying problem, because I can't use exit pre-signals both ways if there's a crossing. And it also doesn't solve my station problem

Korenn, that seems nice, but imagine if I have 5 or 6 goods trains.. and the wood trains get delayed for some reason. In that case I think the goods trains would fill all the platforms and the wood trains wouldn't be able to deliver. And don't tell me to use 2 stations

Thanks for the suggestions so far, by the way

[mpettitt]

Korenn, that seems nice, but imagine if I have 5 or 6 goods trains.. and the wood trains get delayed for some reason. In that case I think the goods trains would fill all the platforms and the wood trains wouldn't be able to deliver. And don't tell me to use 2 stations

Use one station with more platforms! Or build an entrance loop for the goods trains (with a checkpoint) so they queue for their platforms out of the way and your wood trains can get in without problems.

[wizeman]

I'm sorry to be so persistent , but more platforms doesn't work. Then I would have to add 1 more platform for each new (goods) train that I buy. If I had 10 goods trains I would need at least 11 platforms..

The loop entrance would work, I guess. Just not what I was looking for

Anyway, the developers should check the signal thingy. Maybe I'll look into it myself, if I understand how the rails are packed into the map array

[wizeman]

Just to make it clear, I can make it work in various ways.

I just think it would be nice if the signals took into account the actual rail connections, not only if there's a rail in that spot. I think Lilman424 understood the problem.

I was trying to tell where this would be useful, in my game specifically. I just think this behaviour doesn't make sense.

You don't have to fix this, I know there's more important things to do, I thought someone would find this problem useful and simple to solve. I'll try to dive into the source myself and see what I can do

[mpettitt]

I'm sorry to be so persistent , but more platforms doesn't work. Then I would have to add 1 more platform for each new (goods) train that I buy. If I had 10 goods trains I would need at least 11 platforms..

The loop entrance would work, I guess. Just not what I was looking for

If you have all your goods trains coming in at once you need to work on the layout a bit. Running 10 trains of goods out of one factory is a surefire recipe for congestion! You could build a relay station and have a single train doing a full load-unload run to spread the load a bit, or, better still, collect goods from other places on the map. If there are no other goods supplying industries, fund some!

[lucaspiller]

Here is a nice simple way for you, replace the cross over with a bridge! The wood trains will still be able to get in without problems and so would the goods trains. If there isn't enough space they will just queue up. This would also mean that a goods train and wood train could enter at the same time.

[wizeman]

Thank you lucaspiller, I think that's what I'm going to do in the mean time.

I was trying to make it a little more efficient. You can't see it the original picture, but what I was trying to do was letting the wood trains able to use any platform. I almost did it, the only problem I was having was that signal

[dominik81]

I don't think any of you really understand what I wanted.

habell and Darkvater, the problem is that the signal is green when the top 2 platforms are free, but there is no way to go to those platforms.. no train can turn in a crossing like that, so the signal shouldn't account for those platforms. Really! Watch closely.

Of course it has to account for those platforms! Signals are mainly to prevent crashes and if that signal wouldn't be red, you'd certainly have crashes.

[wizeman]

Of course it has to account for those platforms! Signals are mainly to prevent crashes and if that signal wouldn't be red, you'd certainly have crashes.

I see what you mean, but notice: the problem is the signal is *green* when it should be *red*, not the other way around.

The signal should account for trains in that whole segment, yes. *But* it shouldn't account for exit pre-signals which aren't connected to it!
You see, why does it matter that there's a free exit, if there is no path from the entry-signal to the exit-signal?

It's a small detail, I know. I already identified the relevant functions in the source code, but it will be a little difficult to understand it completely. Maybe it will not be very straigthforward to do this, but I will do my best.

[wizeman]

Perhaps you should find this version simpler.

In this situation, trains coming from A only use platform 1 and trains coming from B can use all platforms, *but* they only enter the junction when there's a free platform (that's the advantage of pre-signals).

But notice how there is no path from A to platforms 2 and 3, yet the A signal is green.

What happens is that if another train comes from A, it is going to pass the signal and then it will be stuck. Now even the trains coming from B cannot enter the station!

Now tell me if you still think that signal is right.. It is possible to make it right without altering the general behaviour.

You just have to take into account this: if the exit-signals 2 or 3 turn green, *only* the entry-signals which have a path to 2 or 3 will also turn green (if there's no train in the segment, of course). In this case, it would only be signal B.

Of course, trains would have to be accounted for in the whole segment.

I hope this clears things a bit.

[Hunter58]

Just bumbed in on this thread.
The problem with the pre-signal is not specific for openTDD. I tried the patched TDD version and it behaves exactly the same.

[Bjarni]

I thought (and talked) about the possibility of having entrance signals, which only targets some exit signals a long time ago (when the presignals was new in OTTD)
the problem is that it's rather hard to code due to the way signals works in the code