AI priority?

[sniper297]

Here's an interesting one, got two AI trains in an opposing meet, what decides which one gets priority? I always assumed first come first served, but this;

Standard right hand running, standard signaling, both trains have Drive to trackmark then wait for 5 seconds instructions (ensures a full stop before the single track section to reduce the number of SPADs). Odd part here is the train from the left (green line) always takes priority unless he's a long long long way off. If he arrives at his trackmark first while the train from the right (blue line) is still approaching his trackmark, he takes priority as you would expect. But if the train from the right arrives before the train from the left, he waits his mandatory 5 seconds, then sits and waits while the train from the left comes to his trackmark, stops, waits his 5 seconds, then goes through. Speed limits are 20mph on that section from both directions, track configuration and signals are symmetrical so there's no reason why the right train should wait if he arrives a minute before the left train.

 

[Kris94]

I'm assuming which ever train has the lowest number. 1=primary(hot intermodal trains usually always gets first jab unless entering a long distance single track line and a train is occupying it and coming in the opposite direction.) 2=secondary(any other mainline train). If both are 2nd priority, then it always goes for the most valuable cargo. 3=branchline and locals.

 

[sniper297]

Not the case here, identical 40 car trains with 3 engines, default priority 2 for both. Has to be something about the signals and/or switches leading up to it.

 

[Kris94]

Well I don't know. I'd just change the priority. Might have to tell to stop schedule. Then change it. But I've done it with no luck. So you might be stuck on this one.

 

[Kennilworth]

Hi

Priority has nothing to do with which train gets the junction first as far as I know and is only used to keep the train on a particular track. A train set to priority 1 will run on priority 1 tracks wherever possible. The same with priority 2 or priority 3 trains and tracks. Both trains and tracks are given priority 2 by default.

As far as I am aware the only other use for priorities being set on trains is where the ATLS crossings are being used. The triggers can be set to react only to a train with a particular priority. This means that you can have a trigger further away from the crossing that only reacts to high speed trains and a second trigger that only reacts to low speed trains much nearer the crossing.

Regards

Brian

 

[REISCOOL]

What I'd do is set up the meet like you were in Train Order territory (i.e. no signals). Put a trackmark at the end of the siding where you want the train to stop and a trigger on the mainline (past the siding), tell one train to navigate to (or drive to, depending on your preference) the trackmark, then give it a wait until trigger command that makes it wait until the oncoming train hits the trigger on the mainline. Then you can continue that train's schedule as normal.

In other words, It's simpler to define the priority yourself using the driver commands instead of letting the AI decide it for you.

 

[llebrez]

Just a thought: Go to surveyor and put a trackmark over anywhere in the area (track), then look at the default-direction of the trackmark. Now move it around the track and see if it changes direction. Sometimes the way the track was installed could make a difference. I know some will disagree with that, but you have eliminate possibilities. just in case...

 

[stagecoach]

You dont show which way the default junctions are set at. This could influence the choice. And the signals on the single section will play a big part in that.

 

[sniper297]

Sierra Hotel!

Give the man a cigar, that's probably it!

Switch at the west end set for the train from the left;

Switch at the east end also set for his route by default, that's why he takes priority. I suspect the trick is to set the trailing points for the right hand track at all single track sections, so as an AI approaches the chokepoint he already has the trailing point switch set for him, and he only has to throw the facing point at the other end.

 

[maruffijd]

When I have section that goes double to single back to double, I use the ASB Crossover asset group to set it so it is always first come first serve through the single line. I have never had any issues with the fist come train yielding to anyone in the distance as well as no cornrow meets.

 

[boat]

When I have section that goes double to single back to double, I use the ASB Crossover asset group to set it so it is always first come first serve through the single line. I have never had any issues with the fist come train yielding to anyone in the distance as well as no cornrow meets.

Mmmmmmm

I’m intrigued how you do that as ASB Crossover wasn’t designed for that. It’s really just for diamond crossovers.

I can see how you might fool the system into thinking the two approaching directions were opposing diamond crossover directions... but ASB Crossover has no control over the turnouts so Trainz AI will do its own thing there. I would have thought that would lead to conflicts and failures.

Does it not?

Boat

 

[maruffijd]

Mmmmmmm

I’m intrigued how you do that as ASB Crossover wasn’t designed for that. It’s really just for diamond crossovers.

I can see how you might fool the system into thinking the two approaching directions were opposing diamond crossover directions... but ASB Crossover has no control over the turnouts so Trainz AI will do its own thing there. I would have thought that would lead to conflicts and failures.

Does it not?

Boat

No sir, I have not had any problems with AI trainz controlling juctions. I set the activation triggers just far enough out to allow the proceeding train to have just enough time to steal control of the exit junction when the waiting AI releases control for a split second trying to change the red signal.

It's a bit sneaky, yet, it works perfectly for me.

Alternitive method is to overlap stretches of double track so give the appearance of a Double-Single-Double, thus eliminating the active junctions. (placing a junction on overlaid invis, detached track gives the illusion of a junction)