Transport Tycoon Forums

I went through the wiki and this forum and I just don't get it.
How does the advanced depot from the wiki work? (this one)

Why are there 4x 2-way signals? (pre-entry and pre-exit)
Why are there an additional 4x 1-way signals facing into the wrong direction?
What's this strange loop for anyway?



I'd appreciate if anyone could help me understand this.
Thank you!

Those things that are facing the wrong direction and the 2 way signals are priority lanes, they make sure that trains on the line can keep moving without being interupted by trains leaving a depot.
What happens is that the presignals all turn into read when a train enters the "block" of the exit signal, this way trains leaving the depot get a red signal while there isn't actually a train blocking the line yet but they'll stop anyways. The signals will turn red again when the train on the line leaves the priority block and the train comming from the depot can join the line.

Build this in-game and take a look how do the pre-signals react.

Yeah, those priority lanes took me a while to figure out as well. They're not very intuitive at all. If I were to make a new type of signal, it would be a priority signal. It would have the advantages of taking up less space, be intuitive, and probably less prone to mistakes. Don't know how I would actually implement it though.

-Hazelrah

my idea.

note Screenshots were edited in paintbrush.

the idea is for a "Reversed Combo Pre-signal" AKA Priority signal. the way it works is that you place an entrance pre-signal on the low priority lane, and a priority signal on the high priority lane. the priority signals are stackable like a combo.

the way it works is, you have a standard signal in the direction you want, and a virtual combo pre-signal in the oposite direction. exampes in attachments. the top junction in the screenshot is a representation of how it should work, and the bottom 1 is how it should look.

Note: the key note is VIRTUAL combo signal in the oposite direction, a reversing train should see the back of a 1 way signal, and therefore not be able to pass. as for 2 way signals, i don't know how it would work exactly...

i came up with this method to minimise the number of new signal types required, as you can see, its only 1 extra signal type. it is possable that a low priory signal could be invented, in which case it would basicly duplicate the function of an entrance signal. you could then however add special logic to prevent priority signals interfering with a pre-signal junctions, but i don't see how this is required.

I've heard that priorities are not needed with a new pathfinding... well, anyways.

Here's a picture of a better(?) solution: leave room between lanes, like L__R, so it's easier to connect more lanes. Also, with that you could build the priorities into inside lane. When priority extends straight from the another track's entrance point, the system works as well, even a bit more efficient, and you don't need that extra 2-way combo signal.

i don't see how your top 1 works.. looks incomplete. however, it does still require the priority zigzag, these priority signals i sugested would eliminate that. yours is basicly the same as the picture at the top.

also, i don't see how a path finder would automaticly solve a priority problem, since prorities require stoping or alowing down the train on the less important track.

Oh yeah, sorry, made it in the wrong side ;P

I guess I must have thinked about doing 4-lane stuff .. or something. Well, it's a pure mistake anyways.

I'll attach a new, eh, better thought picture what I meant to do. Hopefully I got it right this time

And of course the depot could be built nearer the entrance, to give the train room to accelerate after leaving the depot.. but.. it.... sigh. I give up.

yes, like i said, basicly the same 1 up top, except that instead of between the depot and lane, you place the priority zigzag at the other side of the lane, between the 2 directions. my solution eliminates the zigzag completly, with the same effect. its basicly a space saving signal, and probably a lot easier to understand.

anyway, please continue any further discusion about my idea here

Of course, but since the signal doesn't exist, I was just trying to help to cope with the current stuff

Those priority setups are very good i admit, but they are hardly easy for a beginner to use. And also when your strapped for space, ie only have 2 squares wide and no room for a big thing like that, then a new signal type for priority would be amazingly useful, especially with yellow signals (hint hint!)

i don't know what yellow signals actually do... but i was going to take a loot at the yellow signals GRF and see if i could modify it to make a GRF with yellow signals and this extra signal type.

EDIT: Making it yellow signal compatable isn't going to be easy due to the the fact that yelsig.grf is just full of sprites and no code... getting OTTD to distinguish between the signal types is not going to be easy because it is curreltly almost entirely built into OTTD.