Red Lights are driving me mad!

[LARCO753]

Hi, can anyone please help me? I have been building an activity (MSTS) and when I run the activity to check it works, my drivable train pulls into the station and up to a red light as expected.
The train in the traffic approaches the station but is itself halted by a red light preventing it from coming into the passing loop at the station.
How can I get the light to change to green so that it can enter the passing light and allow me to proceed?
I would be extremely grateful if someone could help as this is frustrating me as I cannot get my activity to work in the way that I want it to!
Thanks,

Dave.

[timbooth]

Can you post up an AE (or Track Viewer) screenshot showing the loop and signals - its difficult for people to help without knowing the trackwork and signals involved.

I suspect you need an extra signal to allow the passing train to enter the loop, which would be placed just before the tracks converge again.

[choccy]

Single lines are very difficult to get the traffic flowing in MSTS. The signalling system leaves a lot to be desired and there has been lots of correspondence on this very problem on this site. If you do a search you should come across lots of contributions. Stand offs in MSTS are easy to achieve!

If you look in AE you will see how many signals turn green ahead of your player train; it will be the same number for the AI trains. On some routes it's 3 and on others 4. Once a train has claimed the signals it's also claimed the points in that path so if you look at the point immediately ahead of your player train you should see that it is switched in favour of your player train and not the AI train that needs access to the station.

To get round this you need to change the time(s) the train(s) start or alternatively slow the AI train down. You can alter its initial speed in AE and also its speed between stations, whether it be passenger, goods or light engine.

This is not an exact science, alas, and trial and error coupled with frustration will be present. Even if you get the traffic flowing in AE there is no guarantee it will work in the Sim. The video in AE doesn't even make a good guess as to what speed the user train will travel and, while it's often right for AI trains, it makes a hash of it where gradients are present.

When you run the activity note the times your player train passes various signals and also at what time you meet a moving AI trai and where. You can then compare them with the times shown in AE and make some more calculations from there.

Mark

[LARCO753]

Thankyou for your assistance, I will try to persevere with atering the departure tmes etc.

Dave.

[spontin]

I've been testing almost the exact same scenario but while I have been able to get the AI train to enter the passing loop and the driveable train to leave, I cannot get the AI train to leave it's loop and carry on down the line !!
I've found that adding signals to control the driveable train's direction but none on the AI down train's direction works fine but obviously not realistic.

I've also found that only having the one signal to control the AI train out of the loop and none further down that path also works !!

So I'm totally confused about why MSTS and the AI routing seem to clash on a path that has no train on it.
BTW - I'm assuming that automatic points are essential in this scenario.
Also does the Passing Loop option in the AE have any effect in this ??

Steve

[choccy]

Automatic points are not essential for trains to pass at a loop; the only problem that may arise with manual points is if you press 'G' on the keyboard it will switch the points and the player train will diverge from its intended route!

Once you have got both trains side by side in the loop there should be no problem with both of them continuing their journeys from there, be they AI or player trains. Have you got another train ahead of the AI train or does the path include a double reverse point? It does seem as though you are adding signals in RE, Steve, so it's very difficult to know what's going on without being able to see the precise scenario. Certainly I have never had this problem with AI trains on any downloaded or bought route. Occasionally, with the player train, I've found it necessary to move forwad to clear the signal ahead of me. Now and again, after an AI train has passed the signal does not automatically clear.

As for passing paths. No one seems exactly sure whether they help or not though they do make a difference. Those that advocate them insist that you must click Highlight and then optional path selection for passing paths to be effective.

I remain unsure as to whether Passing Paths help or not. I have known them free up one stand off and then create another problem elsewhere.

Careful timing, lots of patience and a measure of skill will almost inevitably eventually get the trains rolling on single lines, passing paths or not.

Mark

[timbooth]

This example of a passing loop works for me - the AI train will enter the loop allowing the driver to clear. I've not had a stand-off with this setup, and is prototypical. It won't solve priority though - you'll still need to time AI traffic if you want to make AI traffic wait for the player.



Signals A and B are vital, to allow two trains to pass. Too many signals can cause problems - you should be ok with just signals A and B. If additional homes are required, you should really configure the scripts so A/B only clear if all the homes of the single track section ahead are clear.

I've so far setup two loops in series this way and I've not had a stand-off, even with several trains in both directions- one train is always able to move.

Passing loops are not required, though some situations may demand them.

[LARCO753]

When you edit the timetable, is it best to edit the driveable path before the traffic pattern paths or vica versa? Will that help to prevent the traffic train from getting held up at the lights.
I have altered the timings by 10 mins either way but each time without the desired effect.
So frustrating or what?

Dave.

[choccy]

It doesn't matter which you edit first. It may be best to alter the time of one of the trains rather than both. It's impossible to say much more without seeing the precise scenario with with which you are trying to deal. Mark

[spontin]

I've set up a loop track in the same mananer as Tim's described with the signals as shown and also mirrored so that the same logic will apply from either direction.

Now if BOTH player and AI train are started at the same time - all is well and depending on path length into the loop, either will wait for the other to arrive and then pull on through.

The problem arises when the AI train is started later than the player.
The player is signalled all the way thro' and when the AI train starts, the player signals change to reflect the line is blocked and allows the player into the loop BUT the AI signal allowing the train to enter the loop stays at RED.
It looks as though MSTS allows signal logic to change but the path & points logic does not reflect the change and since the player train has grabbed the path & points, it does not release these afterwards.
It also seems that the pathing logic is not dependent on the signalling blocks either.

Does this reflect other peoples findings?
Tim - did you find this or did your AI trains start at the same time as teh player.

Steve

[timbooth]

I did test the loop with the AI train delayed by 15 seconds, and it didn't make any difference.

Where did you start the trains? I had two loops set up either end of a single track section, and started the player and AI train from in the loop at each end. If you started the AI train on the signal track section, then that would be a problem.

If you start the AI train on the single track section, then it will be placed on a path selected by the driver. With the AI train starting in the loop, it will have to wait as the driver has already grabbed the path.

Remember that signals are just responding to track status, according to their scripting - turnouts can change without affecting signals, depending on the layout, traffic, and the scripts.

You could try removing the signals before the loop, leaving just A & B.
The entry signals could allow two trains to head down the single track.
Ideally signals A&B should be set to clear only if the entire single track section is clear - and not just up the next home.

I'll do some more testing over the weekend.

[choccy]

However good the signalling I fear you will never be able to resolve this problem entirely satisfactorily. When standard pathing is used once MSTS has assigned say 3 clear signals to the player train (the same logic applies to AI trains) the last of which is the exit signal from a loop, a stand off will be inevitable if an AI train is approaching on the single line the other side of the loop. In the Sim the exit signal will revert to danger with regard to the player train but the point will remain irretrievably switched in favour of the player train, be it automatic or manual.

If the trains are to pass the following scenario must be set up. The last of the 3 signals claimed by the player train must be the signal which permits it to enter the loop (its exit signal must initially be red). In precisely the same manner the last of the 3 signals in favour of the AI train must be the signal which permits it to enter the loop from the other direction. This is easy enough to set up as a test, where just one loop is involved but a different proposition on a line with many loops. Sadly if it works in AE there is absolutely no guarantee it will work in the Sim because the trains will not travel at the same speeds as they do in AE.

So far all my activities have been on single lines, Cambrian and SMJ, and I've always got there though inevitably slowly. (The Cambrian is particularly difficult as 4 siganls clear ahead of the trains, and loops are few and far between.)

One little ruse may help and that is to place a double reverse point on the player path in the loop, then the exit signal and path for the player train will not be set up. It's not entirely satisfactory though because, if the player train has to wait for the AI, the signal will not clear until the player train moves forwards.

I do have experience of points being switched after being claimed when passing paths are used, but the system is not reliable and, on one short activity I compiled only as a test, the signals acted like traffic lights. I drew into a station, and stopped with the signal to exit the loop clear. Then an AI train approached and the clear signal changed to danger during my station stop, and cleared after the AI train passed. The points also switched. Crazy!

Mark

[spontin]

Here's the layout........
<IMG width="631" height="206" SRC="http://www.atomic-album.com/showPic.php ... TSLoop.jpg">
Hope its clear enough.........
Tim, I start both trains at either end on the single tracks heading toward each other.
I have extended the layout to include another passing loop in series and again single tracks at either end. All is OK if trains start at same time but problems when AI is delayed beyond the time where Player is routed and signalled into the passing loop. At this point if the AI train starts, signals change to hold Player in loop but access to loop is prohibited to AI train by the entry signal staying at red even when Player is stopped in loop at the red signal.
BTW - I have changed the SignalNumClearAhead parameter for the 2 aspect signal that I'm using in all these to 2 to see if this helps at all.

Choccy - thanks for your input. I'm beginning to believe that I'm up against MSTS limits to mimic the movements I want for the Talyllyn.
I glad I didn't include signals the the route (as theTalyllyn doesn't use them - works off staff & block sections) so this exercise is purely one for me exploring if it could be done!

Steve

[timbooth]

I think your problem is you are starting the AI train on the single track section, which is already allocated to the player train - you should start the AI train in a loop so it won't be in the way. You can still make the AI train grab the path - start its path right before the signal and give it a starting speed of say 15mph. That forces it to grab the path up to the next signal, the player train is then signalled to wait.

I set up two loops and started the AI train 15 seconds after the player train, and the AI train will wait if its starting from stop - but if starting at speed, it will get priority and grab the single track from the player.

The only stand-off I get is when I start the AI train on the single track section - though it might be possible to start the AI train at speed so it clears its signal first, providing the player train is far enough from the loop. I'll try some more combinations later.

If you make the player train start before the loop, then it allows the AI train to grab its path.

The main problem with MSTS is lack of priority - if AI trains could be set higher or lower in priority then it would of reduced the chances of stand-offs, as well as improving traffic flow.

Stand-offs can't always be avoided, as there always needs to be a clear block for a train to move into - if two passing trains were too long then it would be impossible for them to pass each other.

[spontin]

Thanks Tim
I'll try the "at speed start" and see.
What I don't understand however, is why if I manage to get both Player & AI into the loops at the same time and the player leaves, the AI train does not get clearence to proceed down the line when there is obviously no other trafiic in its way. I've assumed that this must be related to the lack of signals down the line??

The ideal scenario that I like to setup is for the player to arrive in the loop and wait for the AI to arrive and pass. I think it adds to the presentation of the activity to see other trains arrive and pass around you.

Appreciate you help - I'm feeling my way into route signalling as I didn't need it for the Talyllyn as I said before (thank goodness)

Regards
Steve