Left-turn Trains

[jeffryfisher]

I just saw yet another impossibility: Two trains were heading toward each other (on double track). At an 'X' intersection, each turned to its left, across the other's path. However, they passed through one another, like they do at a diagonal point. I'm not sure how this happened. I did not see the moment of arrival at the intersection. Maybe they arrived simultaneously.

[Gwizz]

I've seen this happen before.

I was told by PopTop that the cause was that the RRT2 game engine had been programed to its' limit. 

That there was a lot of features that were cobbled together to the point that the team wondered why they even worked at all.

It is the reason that player made changes are a tough go to make function correctly.  There is little programing space to work with.

Although, I've enjoyed trying to exploit  these bugs in my maps.   

I haven't done much map work lately with a family member, now on the injured list, needing most of my attention.

[cogeo]

This happens when two diagonal sections of track intersect, but only if the intersection point is not in the middle of a cell, but instead on the corner (of the four adjacent cells). Check the "Grid" option (Ctrl+G) to see this more clearly.

[jeffryfisher]

This happens when two diagonal sections of track intersect, but only if the intersection point is not in the middle of a cell, but instead on the corner (of the four adjacent cells).

That feature is well known to me. However, what I observed was two trains sharing a cell as each turned left through the other (intersecting in two places).

[Superchief]

I just saw yet another impossibility: Two trains were heading toward each other (on double track). At an 'X' intersection, each turned to its left, across the other's path. However, they passed through one another, like they do at a diagonal point. I'm not sure how this happened. I did not see the moment of arrival at the intersection. Maybe they arrived simultaneously.

If you play my Pre-Conrail there are a few 90 degree crossings where trains never stop when trains head toward each other.

[jeffryfisher]

If you play my Pre-Conrail there are a few 90 degree crossings where trains never stop when trains head toward each other.

Do they share a map cell while crossing? Most likely, they are on diagonals intersecting at a grid point. This is a "well known" way to cross tracks without stopping trains.

There's one other way I've seen, and that's when one train has just turned at a station. Its cars can be ghosted so that another train crossing its tail can pass through them.

[Superchief]

Do they share a map cell while crossing? Most likely, they are on diagonals intersecting at a grid point. This is a "well known" way to cross tracks without stopping trains.

There's one other way I've seen, and that's when one train has just turned at a station. Its cars can be ghosted so that another train crossing its tail can pass through them.

Yeah, they do.

I wonder if it was programmed that way in order to stabilize game flow...

[Gwizz]

Yeah, they do.

I wonder if it was programmed that way in order to stabilize game flow...

If I remember correctly Pop Top said over the sides was a normal grade crossing.

Over the corners was an above ground crossing, programed for no stopping.

Turning at a corner must be some sort of programing compromise.

[Superchief]

Ah, okay.

[jeffryfisher]

If I remember correctly Pop Top said over the sides was a normal grade crossing.

Over the corners was an above ground crossing, programed for no stopping.

Turning at a corner must be some sort of programing compromise.

I don't think so. Normally, when one train turns left in front of another, one of them stops. The instance I observed must have been a rare coincidence of timing that allowed both trains into the same square before either turned left to block the other. Has anyone else ever seen it happen? I think if it were a programming compromise, then it would happen all of the time.

[akuenzi]

Maybe this is something for the 'wishlist' of an Open RRT2. Given the scale of the maps, it would seem nice if there would be NO delay for trains crossing over one another, with maybe a couple exceptions:

1. A train crashes. Okay, I'll buy that -- this would likely cause a significant disruption to traffic while the mess is being cleaned up.

2. There is only a single rail being traveled on. This makes some sense, too, but the delay doesn't seem like it should be as long as it currently is in the game.

If a train is using double rails, and everything is open, it seems one train should pass seamlessly through another. Presumably somewhere in there it would have opportunity to pass. It just doesn't seem realistic to have a train that spans hundreds of miles, and that this holds up another train. It doesn't seem realistic to have a train paralyzed for 'decades' waiting for the line to free up.

[Gwizz]

I just deleted double posts. Should make the thread easier to read.

[TheDS]

I think this is one of those rare instances where it was treated like two right-turning trains. I can't say I recall a pair of left-turning trains in the manner you describe stopping unless one was in fact going straight. But I've slept a few times since the last time I played, so I could be remembering wrong.

[outofmage]

Well, it's because the train was considered as a POINT in the program. This point is on the very front of the engine. The small white triangle in the trains detail screen is the trains' points. Since you cannot bulldoze the track when there is a train running on it, therefore if the Point can go through somewhere, the whole train can go through it after.

This works almost all the time except the situation the jeff pointed out. In this situation, since it's a double track the two trains which considered as two points have never gone cross each other. It's hard to explain it in text, I do it in 4 pictures.

Here is the link:

[jeffryfisher]

Well, it's because the train was considered as a POINT in the program.

I am unaware of any other instance in which a train is treated as a point. Usually, if any part of a train is in a cell, then no other train can share or cut through the track that it is using.