Choose signals force also trains which only go through

[Václav]

I found something what is not real bug - but very bothering thing - behaviour of choose signals. It is very bothering that trains which only go through ignore these signals - and it causes jams that can stop all movement on rails.

You can count following as evidence for reason why to change it: In real world freight trains use free rail to go through station in which they don't stop - and at every time it is different one - it is not rail that creates the shortest connection. And for example, one train line between Prague and Brno goes through Kolín without stopping there - and it also uses only free rail (I have already seen that train on rail without platform or on rail with platform number 2).

I would like to suggest improvement of this behaviour.

[Emil Sawicki]

I'll give another example. Now my stations looks like this:

6            /-<-----------\
4          /------------->-\
2-------+--------P-------+-<C---
1---C>-+--------P--------+------

There are four numbered tracks: two bidirectional passeenger ( P ) platforms without signals and two one-way tracks with one-way signals ( </> ). All trains goes through choose-signals ( <C/C> ), but only passenger trains have platform (nr 1 and 2) in schedule. Freight trains have one-way tracks (nr 4 or 6) in schedule.

Now, there is a freight train (X) on station waiting for signal, one freight (Y) and one passenger (Z) train incoming:

4             /-<-X---------\
3           /------------->-\
2-------+--------P-------+--<C--Y--<--Z--
1---C>-+--------P--------+----------------

Z (pax) train have to wait, until the Y doesn't go to track 4. Y can't go on other track, because it passes the station.

If the choose signal allows choose a platform to trains, which only passes the station (as Vaclav wrote), then trains will not have to wait. I want my stations looks like this:

4             /------P------\
3           /--------P------\
2-------+--------P-------+--<C----
1---C>-+--------P--------+--------

There are no one-way signals on the station, both freight and pax trains can go to any platform.

[Václav]

Thanks for support, Emil.

... and of course, problem is not in stations where trains go in only one direction. There they simply wait until way is free, problem is with station where are bidirectional tracks - and mostly where some trains wait until they are loaded.

To explain it better I use Emil's final scheme:
Track 1 - freight train (that arrived from left - so descirbed situation is for this case; but the same situation would be if by platform on track 2 will be waiting to be loaded freight train that arrived from right) is waiting to be full loaded
Track 2,3,4 - empty

Train what will arrive from right side will pass right - because its short way is empty.
But train what will arrive from left side blocks all other trains because:
1. its short way is blocked
2. its choose signal glows green and so it pass this signal - but pre-signal glows red and so it stop here
3. tracks between choose signal and pre-signal is used by train that arrived from left
4. pre-signals shows blocked way also for platform on track 2


4       /------P------\
3      /--------P------\
2-----+--------P-------+--<C----
1-C>--+--------P--------+-------


... and I am not sure if long signals would solve this. Else I would not suggest this.

[Ters]

Why not just keep trains waiting for a full load away from the straight through tracks? Those of my stations that look somewhat like your examples split the full load trains away from the straight through tracks, either to a choose signal or to a dedicated platform for that line, using waypoints. That leaves the straight through tracks for traffic going through without stopping, as well as trains that only unload or that do not wait for a full load, since these get out of the way quickly.

[ӔO]

If there is room, I would just dig the straight line underground after branching the station enter/exit to the sides.

T = tunnel

1   /-----+-----P-----+----\
2-/-T  \-+-----P-----+-/  T-\-
3-\-T  /-+-----P-----+-\  T-/-
4   \-----+----P- ----+----/

there's something similar at the largest station in my city.

[Václav]

If there is room ....

If there is a space where it could be built, it would be splendid ... but mostly it is unavailable way.

... and by the way, I currently found that idea with long signals does not work - and is irrelevant if signals are in chain long signals - choose signals or choose signals - long signals.

[prissi]

Make the freight trains long than the passenger platforms. Or give the freight trains a sceodn choose signal on the sideline. Then choosing will only start there.

[Václav]

Make the freight trains long than the passenger platforms

When some trains freight trains are long 7 tiles and else ones are long 8 tiles (like stations) - and when main platform is in row with rails that come into and from station, it is hard.

Or give the freight trains a second choose signal on the sideline. Then choosing will only start there.

Hard to do on station like is on attached picture.

[ӔO]

alternatively, how about having just one platform there to the side and putting a larger rail yard down the line where there is more room?

[Václav]

I am sorry if following words will sounds someone very bad:

This case remembers me problems with display settings dialogue and layer view. There also some people tried to find many solutions based (mostly) on shortening of text of translations - because it was hard to get for some people that it is usable only for few languages - but after some time my solution (with drag and pull corner) was used - because it was accepted as the best solution.

So why don't use my idea again?

[Ters]

But how is the routing going to know that the train should go throgh the station when it does not have the station on its schedule? If all tracks through the station are occupied (either by waiting trains or other traffic passing through), the routing might send the train back down the other track, all the way around the map through tracks never meant for more than the one train it was built for, and back to whereever the next waypoint for the train was, causing all kinds of problems along the way.

My soft waypoint idea could help this out by saying that the trains should route to a station, but not stop there. The proposed change in how waypoints behave have however made most of my soft waypoint concept redundant.

As for the realism aspect: Freight trains waiting for a full load tend to wait on sidings, not on through tracks. At least on freight stations I have seen, which I admit isn't that many. That real life routing can be a bit flexible is because they operate according to a known time table, and because there are far more advanced intelligences controlling it than we can hope to integrate into simutrans in the foreseeable future.

[Václav]

Few days passed - and I think that a little simplier solution would be making long signals like pre-signals - to prevent train from passing through following sections until they will be empty. And from their behaviour for stations, all would be right - for ever after.

Train would have to wait until track will be empty. And I think it would be easier to make this. Only there is issue that train would block trains waiting behind it - but it is needed evil (smaller than current situation when train will enter into problem sections and block all trains).