[0.17.62] Train Collides into itself

[Marc]

Hello Devs,

I have been experimenting with a 32-64-0 train. The game is vanilla and the train has nuclear fuel. The train found a path into a stone station setup as a loop intended for 2-4-0 trains and crashed into itself. The signals operate correctly, that is allows entrance but turns the last signal to red to cross the inbound track to the loop since the crossing block is held by the train. The train fails to slow for the red signal and crashes into itself.

Here is the 152MB save file. The train next to the player can be simply set to automatic and it will trigger the collision.

[boskid]

Not a bug

Train will not pass red signal if it is because of reservation by another train. Here red signal is because of same train and so it is allowed to pass. More precisely: rail segment after red signal is reserved for this train and so there is no reason why it should wait.

FFF-299:

So in this example, the train is approaching from the right. The problem is, that it reserves the block number 2 twice since there is a special rule, that a train can enter a reserved or occupied block as long as it is reserved by itself.

[Marc]

In fixing the issue as show in FFF-299 which caused deadlocks, they introduced the possibility of the train crashing into itself which is a much more serious consequence than inability to route the train. I'm okay with a train deadlocking and going out moving trains and fixing the signals and move on once fixed. I am not okay with the possibility of trains crashing simply because they routed into areas they don't belong. They can do so at any time. I tried solving it with multiple null train stations but even then I get trains going where they shouldn't.

I strongly disagree that their fix to the original issue is a better solution due to the serious consequences of the fix.

[boskid]

No.

I mentioned FFF-299 to show that there is "official note" about train passing on red signal. Only thing that was fixed by mentioned issue was possibility of two trains entering same rail section because ones reservation was released too early - two trains could collide with each other. Train colliding itself on tight roundabout always existed (as i recall)

-- edit:
Ref: 62183

[Marc]

Thank you for the reference to a previous complaint. I didn't see that in my search.