[Patch] Realistic level crossing (safer)

[Eddi]

The train should be held at a signal in rear of the crossing, this signal should not clear until the crossings are clear.

Because that is so realistic.

I think even Belugas might agree with me on this one.

That's how it works in the UK... feel free to disagree but I will require citation.

in germany, trains are required to stop in case of MALFUNCTION of the crossing security (bars, lights), there is never mention of making sure the traffic clears the crossing.

besides of that, the gameplay effect of such a "mandatory stop" would be too extreme. the intention of the original patch was to give road vehicles enough time to clear the crossing, not to stupidly block trains (which, in "reality" is to be avoided as good as possible)

[DaleStan]

That's how it works in the UK... feel free to disagree but I will require citation.

I don't think it needs a cite.
What is the stopping distance for a train at operating speed with a mile long coal rake? What is the time required, at operating speed, to travel that distance?

Given those two answers, what happens if a vehicle enters the crossing 45 seconds before the train was going to enter the crossing? Specifically, is the train physically capable of stopping before entering the crossing, and if not, how does the train manage to yield to the vehicle?

(At a typical US crossing, per Wikipedia, the first automatic warning device will operate when the train is about 30 seconds away. The train will begin sounding its horn when it is around 20 seconds away.)

[belugas]

The train should be held at a signal in rear of the crossing, this signal should not clear until the crossings are clear.

Because that is so realistic.

I think even Belugas might agree with me on this one.

I Do !! I Do!!!
But... after all... I'm on the North American continent too

And I agree with you on more than just this subject

[michael blunck]

in germany, trains are required to stop in case of MALFUNCTION of the crossing security (bars, lights), there is never mention of making sure the traffic clears the crossing.

Not only in Germany, see http://www.tt-forums.net/viewtopic.php?p=747104#p747104

That's how it works in the UK

You North Americans and Germans should be aware that the typical UK crossing is quite a different kind of thing.

regards
Michael

[audigex]

I'm pretty sure that in the UK a crossing is closed >30sec before a train gets there, on account of the fact I've sat for over 2 minutes waiting for a 75mph sprinter to trundle past. That's with the train 2.5miles away if the driver's giving it wigan.

[pavel1269]

edit: made feature, which is currently in trunk ^^

[2007Alain2007]

will this patch ever do more then one level crossing then it wourld be a realy safer level crossing

[sulai]

As gpsoft mentioned, I created the patch "safer level crossings", where trains stop for vehicles, if the crossing is not cleared. Although it makes level crossings 100% safe for vehicles, I gave up on this idea, because trains just shouldn't stop for vehicles. Imagine a jam on a crossing, this would make the train stop forever.

Reserving the level crossing earlier is a first step into the right direction. But in case of a road vehicle jam, thats worth nothing.

Thats where road vehicles need to be a little more intelligent. They need to obey the rule "only cross level crossings if I can safely reach the other side". This picture should explain what I have in mind. I assume 2 vehicles may queue up on one tile.

intelligent vehicles at level crossings.png (5.57 KiB) Viewed 2927 times

a) There are two level crossings ahead the red RV. The red RV needs to decide: drive or stop? Along its planed path, it checks 1) how much level crossings there are, 2) how much vehicles there are on the same lane, 3) how much space is behind the level crossings. In this case, there is 1 vehicle on 2 level crossings. The yellow tile is free, which means there is enough space for the blue and the red vehicle. Red vehicle starts crossing.

b) Same situation, 2 more vehicles on the road. Note: there is not enough space on the orange tile for RV 1,2 and the red one. If this is the case, the red RV checks the next tile along its planed path. 1 more vehicle. Now there is enough space behind the level crossings: 4 RV on 2 tiles.

Its up to design, how many tiles behind the level crossings will be checked at most. I suggest to limit the tiles to be checked behind the crossings to the number crossing tiles. In case b) a 4th vehicle on the level crossing would cause the red RV to stop.

A similar patch to this already exists: http://www.tt-forums.net/viewtopic.php?f=33&t=27184

So maybe we can forbid level crossings for maglev and monorail (way too high speed for crossings of any kind - in real life these technologies don't use the crossings) ...

I like this idea. It makes level crossings safer and it adds an interesting difference between railway and monorail/maglev.

Furthermore, all adjacent level crossings next to a closed level crossing should close, too. Otherwise RV may queue up on level crossings.

[CommanderZ]

So maybe we can forbid level crossings for maglev and monorail (way too high speed for crossings of any kind - in real life these technologies don't use the crossings) ...

And what about the GRFs, that replace monoral with something else...like the Metro tracks in 2cc set.

[Dimme]

Maybe let NewGRFs decide whether crossings are allowed or not?

[crakinshot]

I'm pretty sure that in the UK a crossing is closed >30sec before a train gets there, on account of the fact I've sat for over 2 minutes waiting for a 75mph sprinter to trundle past. That's with the train 2.5miles away if the driver's giving it wigan.

I'm almost certain its interlocked with both tracks, so if the block has been opened for a train, it'll bring the barriers down. Generally though, the signal box sets the path when trains are 2-3 miles away. Not sure, but on the older (manual) crossing points the crossing is interlocked with the signals, to a train cannot be allowed to continue until the barriers are down (or the gates turned).

I guess would need an engineer who knows. If I had to guess I'd say modern systems will first try to lock a block for a train, this triggers the crossing to lock for the train, once a period has passed and the crossing is locked, the signals leading into the block are allowed to ramp-up from danger. This would ensure everything is interlocked so trains cannot pass (ever) if the barrier is up.

That's essentially what this game is missing at the moment, signal/track interlocks. So if you had 4 level-crossing tiles, they would all interlock with the signals controlling those track blocks.