Combined PBS/Pre-Entry(exit) Signals

[Chemical T]

Hello, this is my first post on this forum so I'll start with a quick introduction.
I'm Jisez Manu (Chemical T) and I've been fan of Transport Tycoon ever since it came out for DOS. Back then though, I was young and didn't have a clue how the game worked, but hey, I spent quality time playing it anyway. Since rather recent I have become more interested into the theory behind trains (more specifically Dutch ones, since I'm Dutch). This was also the time I was bored and some way or another I started playing TTD again, using the TTDPatch. I downloaded the Dutch trains and a The Netherlands scenario, after which I've played the game for hours and hours.
Since there was a lot of space for building tracks, and my single track lines were not enough to cope with all the passengers waiting at stations, I started transforming my single track lines into double track lines and made new lines for better connection between those lines (more realism). To make this work, I started growing interest for signalling.

However, sometimes it doesn't seem like the current signals can make some complicated junctions like "Knooppunt Rotterdam" work. In this scenario, there are four different tracks/lines merging for one of my main stations "Rotterdam". As you can see, there is absolutely no way of making that single track double track, thus leading to problems. As far as I'm aware of, it's a more complicated version of the problem explained here. The train leaving has a green signal, while in fact his specific route is blocked further ahead because of a red light. The train will stop in the middle of the junction, blocking the yellow train line, the blue dotted lines (those lines have no PBS signals because they need to have Pre-Entry Signals, plus there is no traffic light at spot Y because that would cause even bigger problems) and even it's own line coming from the other direction! In other words, the entire junction, because no train will be leaving and entering the train station.

Now I've been reading all the development plans regarding signals, and as far as I understood them (some of them are still rather complicated for a rookie signaller like me) none of them have anything like combined PBS and Exit/Pre-Entry signals. What I would like the signals to be like, is that they would be a combination of either a pre-ENTRY and PBS signal, or an EXIT and PBS signal (two different new signals that is). In this case, I would be able replace the EXIT signal that is now green for the combined PBS/exit signal, making the signal look at the train's path AND switching/staying (to) red if the combined PBS/pre-entry signal in the picture (red underlined) is red, too. However, if a train from one of the blue dotted lines want to exit/arrive, of which the path does not cross the red light further ahead, it is able to leave if there is no train using the single track.

I realize this might be a really difficult thing to program, because of the fact those signals would have characteristics from all the different types of signals, but for that reason this is a suggestion on which you can feedback.

PS: other fixes for the problem in my scenario are welcome here too.

[planetmaker]

I think current path signals are all you need. Just replace every entry signal by a path signal facing away from the station and every exit signal by a path signal facing the station and you're done.

[Chemical T]

It seems to be working, brilliant.
Thanks for helping a rookie signaller like me out

Now I've had a similar problem somewhere else too, let's see if it works over there too.

Anyway - is the idea still useful?

[Tve4]

Anyway - is the idea still useful?

Unfortunately not. Current PBS signals are all you need, and they seem to evolve even further.

Honestly, with the advent of PBS, I can't see any need for the older non-PBS signals, and a combined Entrance/Exit+PBS would make no difference whatsoever (PBS always searches automatically for a free path, just like Ent/Exit). With one and two-way path signals you can create much more complex and yet less congested junctions than possible with Ent/Exit system.

Personally, I don't use non-PBS signals anymore, with the exception when playing on large maps and only as automatic block signals (all my junctions are always PBS signalled, most of the time also my doubletrack lines as PBS signalled).

[Kogut]

How I can fix it in non-ugly way?
I try to make realistic scenario.

[Benny]

Entry signal -> PBS signal
Exit signal -> Remove

[Kogut]

But it changes nothing, I still can't place additional signals on island.

[Benny]

No, you can't. And no signals would let you do that.

[Kogut]

Except combined PBS/Pre-Entry(exit) Signals.

[Chemical T]

Actually - if you think about it, I still think there is some use for my idea, but not as a combined PBS/entry-exit signal, but as one stand-alone new signal. It will be based on the concept of a PBS/pre-entry sign signal, but could work on itself.

In the case of the picture attached, the train is allowed to continue it's path because there is a safe waiting spot at the next signal. However, it blocks off the junction, making the train on the side line have to wait until the the train can continue its path. This is a perfect example of 'don't place signals too close to the other side of the junction', and 'replace the basic signals on the side line with PBS signals too and problem solved'. However, except for the fact I disgust trains being able to cross signals from the back, what if I would have to put a signal that is still under development at the place of the X (which would render the PBS useless as a priority signal in this case) or the current basic signal on the main line? I.e. I've been waiting for those limited speed signals for quite some time now, and what if I want to limit the speed exactly after the junction for whatever reason I can think of? The train would, again, stop in the middle of the junction. This would cause traffic jams and just annoy me.

Now my idea is simple. There are two variations. The first variation has to be the new signal (the current one way PBS in this picture). If you would make a new PBS signal with a build-in option 'ignore first (two, three, four, ...) safe waiting spots when deciding it is safe or not', the signal would have to look the SECOND (third, fourth, fifth...) safe waiting spot, and if that one isn't available, the signal will stay red. In this case, the second safe waiting spot would be in front of the second signal after the junction, which in this case, is not safe. The train will stop all the way in front of the junction. This would be very useful for junctions in front head stations, where there is a both-way signal in front of the stations itself (or a single PBS facing the station, which is ugly!!!)
The second variation would be an option in every (basic) (one-way) signal, 'ignore safe waiting spot in front of this signal when deciding path'. In this case, I would select this option for the basic light after the junction itself (which could be a speed limit signal!). The PBS will actually calculate if there is a safe waiting spot after the one you have disabled. In this case that would have to be the second light after the junction. However, there is already a train there, so there is no safe waiting spot. The train will have to wait right where it is now.

[Benny]

Oh, now I get it. But it sounds horribly complex to use and hard to implement.

[Chemical T]

Actually it could be as simple as a hotkey click or button click, and then a slide menu.

Variation one: You make a (new?) PBS signal. Without anything selected you click on that PBS sign. A small menu will pop-up like in the picture. If you can use the arrows to decide how much safe waiting points to skip (possibly up to a limit). 0 is the standard (automatic), 1 and up would be 'customised'.
Variation two: You put the signal I want the PBS to skip. Then you simply click on the signal without any key selected and a button pop ups. If that button is selected the PBS sign will (try to) skip that signal.

The implementation part I cannot judge.

PS: In variation two (which I would imagine to be the simplest to implement) it basically comes down to this: is it possible to (manually) make the safe waiting spot in front of a signal invisible for PBS signals (and switch back to making it visible), so the PBS signal will not recognise that spot as a safe waiting spot and will look behind the signal for the next safe waiting spot? Because in all honesty, the spots in front of the signal at the end of the junction is NOT a safe waiting spot, although the game considers it as one.

EDIT: what would happen, if in variation one, the train cannot reserve the safe waiting spot you have selected it to reserve, because there is another train somewhere down the rails? Well, for that reason you could have the gui in the third picture. Obviously, the selection for the alternatives would be done with those yellow arrows as in the advanced options.

[Eddi]

instead of trying to design a singal that solves your specific problem and that 99.99% of the players are never going to have a use for, you should aim for proper programmable signals.

something along the lines of "force this signal to red if $condition is met."

where $condition may be stuff like: "destination of train is 'Station A' and track at tile (X,Y) is reserved"

there's a half-done patch called "SignalEx" that can be used to implement the storage part, what is needed is a sensible set of conditions that can be entered, and a powerful yet simple gui.

[Chemical T]

Okay I'll take another look at the other suggestions for signals.
Then again, this still is the suggestions forum and I told I wasn't able of judging what the implementation was going to be like. However, I think that my suggestion doesn't seem very hard to implement. Customizing whether a safe point works as a safe point or not doesn't sound that complicated.

Also, I tend to look at OpenTTD as something personal too. Sure you can't expect people to make upgrades for a person if the other 99,9% is not going to use it, but I doubt that a little more choice is a wrong thing (not speaking about the fact I doubt that 99,9% is not going to use this update).

Cheers

[Eddi]

Of course, you can make suggestions all day long, but to turn suggestions into a feature, it must go through a design process of stepwise refinement. i don't want to diminish your suggestion, i want to guide you into a direction where you get the design specs into a shape that someone might pick up on implementing it.

[WWTBAM]

I hope im understanding the original question/sugestion here. I also like he idea and think it could be solved by adding TTDPatch style PBS signals or taking ideas from TTDPatch's implementation and merging them with the current system. So ie allowing PBS signals to also act as entry and exit signals in the direction they prefer to allow trains through.