Traffic Signals in SC4--A Discussion Thread

[Tarkus]

This thread is for the discussion of Traffic Signals/Stop Signs and intersection control systems in SC4.  It has proven a popular topic, which has popped up in other NAM project threads (especially the NWM thread), but deserves its own thread.  I have moved some of the recent posts from the NWM thread on this topic here.

-Alex (Tarkus)

Traffic Signals FAQ
Updated 9/8/2009

1.  Where can I find new traffic signals?
There have been a few custom traffic signals developed, many of which have been released as attachments on this thread.  However, many of them are Lot-based and not animated.  The first true animated set available is Blue Lightning's transverse-mounted signals, which can be found on page 10 of this thread.

2.  How do the in-game traffic signals function with regards to in-game traffic?
The game's defaultstoplight animations are synchronized with the in-game traffic by the use of Stop Points on the Path Files for each intersection, and the amount of time that Automata wait for signals and stop signs is controlled by the Automata Tuning exemplar (Group ID 0xa998d30b, Instance ID 0x00000001).  This file is contained in SimCity_1.dat (Entry #25) and modified in the NAM Automata Plugins.

The three properties that control the signal timing are Street Go Time, Road Go Time and Avenue Go Time.  These are also the only three networks for which traffic signals function properly, and that functionality requires the signal be placed on the same tile as the Stop Point that is affecting it.  Stop Points do not work on the One-Way Road and RHW Networks.

Tarkus has also been developing a set of modular, "pseudo-synchronized" signals, which approximate the game's default signal phase lengths, but are not bound to Stop Point functionality and can be placed in a much freer manner.

3. How are traffic signals animated?
The traffic signals are animated through a series of ATC and AVP files.  While these files were a mystery for years, the ability to create new animations has become vastly easier with the release of the SC4BAB Plugin developed by OverPoP, which allows the export of ATC/AVP animated models through the BAT.  SC4BAB can be downloaded from the SC4D LEX.  Thanks to this recent development, it is very likely you will be seeing more signal development happening here in this thread.

It is worth pointing out that the actual signal, not the pole, is animated.  The Maxis ones consist of one animated model that has simply been copied and placed on the arm or pole models.

4.  How do I add traffic signals or new traffic signal/traffic control configurations to intersections so they show up automatically?
This is done by Type21 exemplar.  See Swamper77's great tutorial here.
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Content from NWM thread moved over to this thread:

edit:  btw, i haven't figured it out yet, but does sim city follow turn on red or no turn on red?

Yup. Sometimes you have to fast foward it a bit for the game to realize the stop light. The automata driving methods are very realistic and so are the sound effects.

Actually, it doesn't--there's no way the game can know to turn right on red.  The traffic signals (and automata reactions to them) are entirely controlled by stop points on the path files, and they're entirely based on cardinal directions (West, North, East, South), so there's no way for it to really tell which way is a "right turn".  It simply thinks of the maneuver as being, for instance, south to east, and the cars should stop at coordinate x,y,z coming from the south.  Turn lanes are possible since you can direct the south-to-east to cross into the turn lane with the paths.  But the game is still thinking "south-to-east", not "right turn lane", so there's no way to exert that much control over traffic signals. 

Further, if you have the stop points defined on the path files, and there is no signal placed at that intersection (signals are placed at intersections by T21 exemplar), the automata will stop anyway, as if there were a traffic signal.

Hope that makes at least some sense.

-Alex (Tarkus)

[deion30296]

Ahhh, That's what I meant. Just bottled up... lol. My Sims are always running the light so I get into firetruck and make em stop.

[Edgware]

Btw, just to clarify. 

It is absolutely impossible to protect left turns at an intersection and have left turn signals turn on at different times, right?  Because if it's at all possible I might try to add it in.

[j-dub]

No. Thanx to the game's designers. You can tell the signal function is very limited, if you notice from the diagonal intersections crossing straight, the diagonal lights are parallel to the ortho lights, depending which side. Take the 8 way avenue intersection for example. From what I have experienced, the Maxis lights seem to work parallel with slip lane intersections, but not the same for the turning lanes. I bet if they hadn't screwed up the diagonal crossings, maybe there was a possibility of at least left turn on green arrow only. Otherwise few people will do their own signals versus the animated Maxis models. A timed prop left turn signal that changes away from the regular signals using the hour system could work, but whose going to want to model that?

[deion30296]

I was watching traffic and all my sims we're being good drivers. Except for this one dude running all the lights... Me. Everyone stopped at red and went at green. Weird huh?

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Now playing: Lauren Hill - Killing me Softly
via FoxyTunes

[j-dub]

I have seen Sims go straight through reds on my game, I know people say that thats not or not suppose to be the case, but I know what I saw.

[zakuten]

My automata pretty much always get out of sync with the lights.. I just figured it was a kind of lag.

[Edgware]

I have posted this outside of this thread.  But what i suggested is a stop sign editing mod.  Which allows us to customize street intersections by place stop signs or removing them.  Is this possible?

[MandelSoft]

Certainly it is. You just need to know how T21-exemplars work.

[Edgware]

oh excellent.  well, t21, i don't really know what those are. I have some stuidying to do before i can mod this...or anything for that matter. 

[j-dub]

Some suggestions on stopsigns rather than traffic lights, and what we already have.
I had posted new stop signs on Heblem's Planning the Mock City, some slightly bigger stop signs that you could actually see they say stop, and still were not too big for Sims. In Heblems case, they worked better because he had alot bigger streets than this game's road network. I think if someone can duplicate the one puzzle piece, T-Road on slope, and also make a X-Road piece as well, and put those stopsigns via T21 on there, we would have a 4 way stop road piece, but there would still be turn lanes. Maybe then even duplicating those puzzle pieces, a second time for a cross road stop, where the T will only have the one stop sign on it, versus 3, and the X would just have a  2 way stop. So thats a way to do it, but in my cities I wasn't too much into those intersections. In real life though, personally 4 way stops with turn lanes and pedestrians, people mistake who has right away or just want to get through before anyone else so obeying the law screws you, and 2 way stops can be just as dangerous, depending where they are, but no one made any street puzzle pieces for 2 way stops. Also, if you notice, that the RHW2xRoad intersection can have stopsigns put on it, and then that eliminates the puzzle piece work. That intersection at the moment could work, unless by next release it gets modified to have turnlanes. I was able to put the RHW2xRoad in neighborhoods and haven't got the no car zot warning, as long as you don't extend the RHW2 past the intersection, this seems to work okay. Other than that, right now at max you can have a 4 way stop intersection with 3 roads connecting to it the most, with the SAM Haleburg's Asphalt street variation. So long as the black street connecting has enough straight tiles away. I have found that very useful, although since its the original Maxis stop signs, they get a little bit into the road when they should be on the sidewalk, but if thats okay with you, you at least have some sort of road intersection with a stop sign.

[Edgware]

well honestly j-dub i didn't understand that much (shows how much i know about modding)

do you have some pictures of what you meant?

[j-dub]

Don't feel bad, traffic related activity is alot of stuff that has to be done. I would mod stuff too, if it wasn't for Vista's limitations, but I'm not going to go there. Well I have some pictures of what you can already do, but let me get back on that.
http://imageshack.rsizr.com/?http%3A%2F%2Fimg108.imageshack.us%2Fimg108%2F3849%2F4waystreetfb1.jpg
This first one is an intersection that you can actually draw stop signs to the road if you have Haleburg's Asphalt street for the Street Addon Mod ending to a 3 way road transition.
(had some problems with imgshack)

[Swamper77]

Keep in mind that adding stop signs to road intersections is purely cosmetic and the automata will use the intersection as if it has stoplights installed. So they won't stop like they do for street intersections.

-Swamper

[j-dub]

I didn't look to see if some RHW interesections actually work that way. Only cosmetic, unfortanetly this issue applies to other games with simulated traffic. Its too bad no one has came up with a work around for this, but games such as L.A. Rush, and Burnout Paradise, its the exact same case where the traffic systems in those games follow off of an invisible traffic signal at a stop point. L.A. Rush especially, all of the ramps don't have a signal, but is programmed like it, because there was no other way, and there is an open 8 lane highway, and all traffic will stop at the intersection following some signal the player can't actually see, and the result is you guessed it, a crash, if you try to go.

[Edgware]

wow that 4 way stop road looks cool.  yeah i understand that this mod if done will mostly be eyecandy but that's fine.  so that road 4-way stop is done with the SAM?  ok i'll try that out thanks. 

[j-dub]

Well since this is the traffic signals thread, I thought to revive it with something I made.



Finished Version.

[Ryan B.]

I suppose I'll throw a couple of my signal BAT development pictures in here:





http://img442.imageshack.us/img442/6333/avenuexavenuetlayl8.png

[j-dub]

The arrows especially are better for the one ways. Would you be able to render the lights with the one color showing up?

[Edgware]

wow those are really nice signals.  are you guys planning on implementing them and replacing the original ones?