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How to prevent road collisions?
Posted: 26 May 2013 17:28
by dgrin91
I have two tracks going over a road on a flat surface with a lot of traffic on the rails and on the road. Every once in a while I get a collision, but Im not sure how to fix this. I have one way path signals on both tracks right before the corssing, but that doesnt seem to do any good. Is there anything more I can do?
Re: How to prevent road collisions?
Posted: 26 May 2013 17:30
by Jacko
road bridge.
sorted.
Re: How to prevent road collisions?
Posted: 26 May 2013 17:33
by dgrin91
So there is no way to safely cross a railroad track without a bridge/tunnel? That would suck and not be very realistic...
Re: How to prevent road collisions?
Posted: 26 May 2013 18:06
by FLHerne
You can make it safer by adding a path signal to the railway several tiles before the crossing (and then no other signals before the crossing). The train will reserve a path across the crossing when passing the signal, and no further vehicles will enter the crossing.
There are still several issues with that:
- If the train is fast, or the road vehicles are slow, the signal must be a long distance from the crossing to allow vehicles time to leave it.
- If there is a queue of road vehicles or a broken down vehicle across the crossing, the vehicles will be unable to leave and be splattered.
- If there are parallel tracks, vehicles waiting for the 'far' crossing will be trapped on the nearer railway line.
In general, bridges are easier, and work better...

Re: How to prevent road collisions?
Posted: 26 May 2013 18:08
by Alberth
dgrin91 wrote:So there is no way to safely cross a railroad track without a bridge/tunnel? That would suck and not be very realistic...
Sure there is, don't drive trains at tracks with crossings!
As for realism, there is already a perfect implementation of reality, we don't need another one.
Re: How to prevent road collisions?
Posted: 26 May 2013 20:05
by Pyoro
Actually, occasional crashes
are realistic, I'd rather say that they don't offer anything for gameplay except annoyance on huge road-rail-networks ^^
Anyways, there's also an old "close adjacent crossings" patch which improves some specific situations a little, I'd say. Hard to say whether it's a statistically relevant effect or not, but looks a bit better in any case

Re: How to prevent road collisions?
Posted: 26 May 2013 22:25
by dgrin91
You cant really call the road accidents realistic, but the perfect signals that never malfunction over 100 years also realistic. If you want to add noise to the system, that is fine (ie plane crashes), but this isnt noise, its something that was overlooked. Its not a huge issue because of bridges (unless the town starts to get pissy), but it doesnt flow with the rest of the game.
Re: How to prevent road collisions?
Posted: 26 May 2013 22:46
by FLHerne
dgrin91 wrote:this isnt noise, its something that was overlooked
Well no - if it was overlooked they'd just pass straight through each other (see road vehicles turning across another lane, or trains passing through themselves on weird track formations). That they collide means that someone wrote code to check for and handle collisions, and that therefore someone thought it would be a good idea (it is).
dgrin91 wrote:that is fine (ie plane crashes)
Plane crashes on suitable airports are very rare, much as crashes with uncongested roads on single-track rail lines, with path signals protecting the crossing, are very rare. Put large aircraft on a small airport, and you suddenly get an unacceptable rate of crashes. Put a frequently-used road crossing on a busy railway, and you suddenly get an unacceptable rate of crashes.
It's all about recognising when you've made your network unsafe, and upgrading it so it isn't (building a larger airport or a bridge respectively).
Re: How to prevent road collisions?
Posted: 26 May 2013 23:00
by Eddi
Not every justification or the existence workaround make a good feature...
there also is now an option to disable random crashes at airports...
Re: How to prevent road collisions?
Posted: 27 May 2013 01:44
by dgrin91
That they collide means that someone wrote code to check for and handle collisions, and that therefore someone thought it would be a good idea (it is).
Collision checking code does not mean it wasnt overlooked. Now I havent looked through the code, but from basic coding principles I would guess that if a bus randomly spawns in the middle of the train track, and then a train drives into that area, a collision would be detected. Thats still an overlook though, because how the heck did that bus get there? Bottom line, the collision checking system was (correctly) not designed specifically with road crossings in mind, so the fact that there is something overlooked in some derivative of the system is very reasonable.
Now my problem with the road collisions is that, unlike virtually everything else in the game, you cant do anything about it. Trains collide? fix/add more signals. Significant train/road congestion? add more tracks/roads. Not moving cargo fast enough? add more vehicles. Planes crashing a lot? upgrade your airport. The only partial exception is the planes, and that is only because of random noise.
The road collisions are not noise though. It is feasible (though highly impractical... and stupid) to set up a system where it will occur 100% of the time. Now thats ok. What is not ok is that there is no direct action you can take against this (only indirect, such as building a bridge/tunnel). I think there should be some sort of signal system like with trains that should be available (and ideally automatically generated, maybe even hidden).
Re: How to prevent road collisions?
Posted: 27 May 2013 07:01
by kamnet
There is a signal system already. As was pointed out earlier, place a path-based signal some distance ahead of your level crossing. The faster the train, the further ahead you'll need to place it, but once the train passes the signal, it will reserve the path across the road and stop vehicles from crossing until after it has passed.
Re: How to prevent road collisions?
Posted: 27 May 2013 09:04
by Pyoro
That'll imo only definitely work for single-line tracks. With dual (or more) tracks you'll always get road vehicles randomly killed. There's also issues with traffic jams; road vehicles apparently don't check whether there's any space to drive off the track, which isn't a very clever thing to do

Re: How to prevent road collisions?
Posted: 27 May 2013 16:03
by dgrin91
Pyoro wrote:That'll imo only definitely work for single-line tracks. With dual (or more) tracks you'll always get road vehicles randomly killed. There's also issues with traffic jams; road vehicles apparently don't check whether there's any space to drive off the track, which isn't a very clever thing to do

Exactly my problem.
Re: How to prevent road collisions?
Posted: 27 May 2013 22:43
by SirkoZ
For multiple tracks situations, the best solution is a bridge or a tunnel otherwise even with programmable signals things would get too complicated as there would always be one vehicle stuck somewhere between crossings waiting to be squashed another day...

Re: How to prevent road collisions?
Posted: 28 May 2013 17:11
by get3
What is realistic about EVERY vehicle stopping on the crossing... in real life you stop before/after the crossing but not on it. There should be a LOW chance that you have a stupid driver looking to get killed by stopping on the track, otherwise unless the vehicle is broken down there should never be a vehicle stopped on the track. My love for trains has caused me to pay attention and in most double+ track crossing there is one signal for both sets of track. For in the double track case (which i use) each direction only activates it's signal but not the other direction although they are side-by-side. So either crossings side-by-side need to have one road warning set or prevent vehicles from stopping on the tracks.
Re: How to prevent road collisions?
Posted: 28 May 2013 18:42
by YNM
There's a patch that makes adjacent crossings also stops. Anybody interested ?
get3 wrote:In real life you stop before/after the crossing but not on it.
Depends - if its going to happen, it'll happen.
Re: How to prevent road collisions?
Posted: 30 May 2013 03:30
by siu238X
To me, the only thing "unrealistic" in this setup is that, on multiple tracks (usually 2), whenever any ONE track is going to be occupied, the whole crossing should be closed to Road Vehicles. But in (O)TT(D) this is not the case.
Surely, getting this bit realistic wouldn't eliminate all crashes, and it IS realistic that local authorities everywhere seek to avoid level crossing whenever possible. So I am afraid that dgrin doesn't have much choice but to find somewhere to build a bridge or tunnel...
Re: How to prevent road collisions?
Posted: 30 May 2013 03:59
by YNM
siu238X wrote:To me, the only thing "unrealistic" in this setup is that, on multiple tracks (usually 2), whenever any ONE track is going to be occupied, the whole crossing should be closed to Road Vehicles. But in (O)TT(D) this is not the case.
I already said
there's a patch for this...
Re: How to prevent road collisions?
Posted: 30 May 2013 09:11
by Pyoro
How difficult would it be to just "turn off" road collisions? Could I just comment out the check for whether train and road vehicle have collided or something, perhaps? ^^;
Re: How to prevent road collisions?
Posted: 30 May 2013 09:31
by michael blunck
get3 wrote:
... in real life you stop before/after the crossing but not on it.
Hoho.
Nevertheless, there might be a certain aesthetics in car crashes.
Alberth wrote:
As for realism, there is already a perfect implementation of reality, we don't need another one.
In "realistic reality" (tm) level crossings are progressively exchanged by tunnels or bridges.
regards
Michael