Priority for trains

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Brianetta
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Re: Priority for trains

Post by Brianetta »

There's a lot of emphasis on "mainlines" here. Not everybody plays that way.

Being able to set a high priority order can be used in addition to all the track priority stuff. I suggest it mainly because it's simple to implement.

Tekky's idea is good, but is not simple to implement at all.
davepoth wrote:With Passenger trains always taking priority if a freight and passenger train of the same priority meet, and then by unit value of freight otherwise.
Not necessary to distinguish between passengers and other freight. One simply has to order the default priority of a cargo by the integral of the line on the cargo profit graph, if one wants to do it that way. Of course, this leads to interesting questions about how to handle the long coal train onto which you threw a single passenger wagon just to provide a socially responsible service...
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el koeno
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Re: Priority for trains

Post by el koeno »

rbn2903 wrote:
el koeno wrote:This is the main thing PPS would do, and really all I need priorities for.
I'd like to mention, that I play with a lot of Passenger/Mail lately (Cargodest + ITIM) and for me there is no main line, just a bunch of junctions. :D In my case a system like PPO (or weak/lookahead reservations) would make much more sense, so that very fast trains would get priority. Although I can see the point in all three systems! :]
And maybe PPO and PPS don't exclude (?) each other? ;)

Rainer
I play cargodest as well, so I know what you mean. PPS and PPO would go hand in hand quite nicely, and I never meant to say that they were exclusive alternatives. Because there would always be situations in which there isn't a clear main line. But in all of my games I would have long stretches of track with a few branches that serve small towns or industries; trains coming from those branches should block anything on the main line. If the main line is quad track you could be able to ease the problem, but often I don't have cash/room to expand my lines that way. Moreover, to me PPS seems easier to implement.
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Re: Priority for trains

Post by PhilSophus »

Brianetta wrote:There's a lot of emphasis on "mainlines" here. Not everybody plays that way.
Maybe I should have defined what I mean by mainline. In my use "mainline" is a line where traffic of multiple other lines aggregates, no matter if you construct it as such. I'm also favoring a more realistic building style. When I access a new industry or town, I often connect it just to a (double-)track nearby, and if you do that multiple times, some lines become "mainlines" just by their selves. I think, unless you are using only point-to-point links, this kind of mainlines just happens, no matter how you play.

I also agree with el koeno that PPS and PPO are not mutually exclusive. In some way there are somewhat orthogonal concepts. With my play style I stumbled across situations where PPS would suite me better, but I see how PPO could be useful for other play styles and I'm pretty sure, that if it was available it would find its way into my play style, as well.

Unfortunately, I don't have the time to make myself familiar with another big chunk of OpenTTD code (YAPP) to do it. I rather keep my focus on timetables and orders for the time being (Brianetta, as a little teaser: I've something in mind that resembles your "operate shared order lists like groups" in some way).
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Brianetta
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Re: Priority for trains

Post by Brianetta »

PhilSophus wrote:
Brianetta wrote:There's a lot of emphasis on "mainlines" here. Not everybody plays that way.
Maybe I should have defined what I mean by mainline. In my use "mainline" is a line where traffic of multiple other lines aggregates, no matter if you construct it as such. I'm also favoring a more realistic building style.
Yeah, that's the definition I use. Whilst I might occasionally have a mainline, I'll frequently end up with a cobweb. Check out any real-life railway map of any early 20th Century industrial city in the UK to see what I mean by that.
Unfortunately, I don't have the time to make myself familiar with another big chunk of OpenTTD code (YAPP) to do it. I rather keep my focus on timetables and orders for the time being (Brianetta, as a little teaser: I've something in mind that resembles your "operate shared order lists like groups" in some way).
Cool. If you could squeeze colour schemes into there too, I'll buy you a pizza.

Order priorities with extra YAPP reservations would probably best be coded by somebody already familiar with YAPP (or at least somebody who knows its interface).
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Re: Priority for trains

Post by audigex »

The thing about priorities is that they only come into play if both trains arrive at a similar time, if the faster train arrives too late to claim the signal, it doesn't matter whether it has priority.

If the faster train looks three junctions ahead, it can still just miss the gap by being a little later. It won't happen on the same occasion, but it will happen all the same - just at a different time, when the faster train happens to be a little further behind
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Re: Priority for trains

Post by Brianetta »

audigex wrote:The thing about priorities is that they only come into play if both trains arrive at a similar time, if the faster train arrives too late to claim the signal, it doesn't matter whether it has priority.

If the faster train looks three junctions ahead, it can still just miss the gap by being a little later. It won't happen on the same occasion, but it will happen all the same - just at a different time, when the faster train happens to be a little further behind
Depends how long your signal blocks are. On my solo games, they can sometimes be 20 or 30 tiles.
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Re: Priority for trains

Post by 555gln22 »

audigex wrote:The thing about priorities is that they only come into play if both trains arrive at a similar time, if the faster train arrives too late to claim the signal, it doesn't matter whether it has priority.

If the faster train looks three junctions ahead, it can still just miss the gap by being a little later. It won't happen on the same occasion, but it will happen all the same - just at a different time, when the faster train happens to be a little further behind
If the faster train is reserving 3 junctions ahead as well then no train will be able to take, or cross, that path.
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