traffic musings: Building a better traffic mousetrap

[Guest CowlFlapsOpen]

By now, any fs9 users is familiar with the traffic density slider. We crank it high and low to find the sweet spot that won't overtax our system yet fill our skies and gates. Add ons like MyTraffic 2006 and Ultimate Traffic have elevated this task to an art form and hushed whispers of awe accompany those who boast having their traffic slider at 100%. Traffic slider setting is status symbol of the FS world. Symbolic, maybe; but functional, no. As most know, the slider only indirectly controls the density of traffic in an area. And density is what matters, since it is what taxes the CPU. People want the maximum number of planes around them that their system will handle comfortably. Every flight plan has a priority percentage attached to it, and the slider is simply a filter: If the percentage attached to a flight plan is lower than the gate, it gets processed. Careful attention to percentage also allows things like the distribution of GA to commercial, vfr to ifr, heavies to lights, etc. If flights plans were created at a constant density across the distribution of percentages, then (other factors ignored, like parking and location) raise or lower the slider would increase or decrease the number of Ai flight plans active more or less linearly. But no system is like that, especially if you have a traffic add on or download AI flight plans and ac. It seems to me we need a two-axis system: One parameter (like the existing percentage) which prioritizes among flight plans (must haves, optional, luxuries, etc.) and one which acts as a govenor on these, keeping the mix of AI in an area around the plane to a preset density based on the user's preference for how much they are willing to tax the CPU. My traffic slider is set to 18% (yea, I know, its embarrassing. I need some of that male hormone enhancement stuff). In most small airports, this setting produces 30-40 AI aircraft in my vicinity (TrafficLook) on the ground around me or in the sky above me. I observe no adverse impact on frames (25+) and am a happy camper. At KONT, in busy SoCal airspace, I get 150+ AI while sitting on the ground. System crawls to its knees (5 fps). If someone built a utility that governed traffic rather than prioritized it, I could say "give me 40 AI in my range, no matter where I am at, and eliminate or add as needed depending on the priority indicated by the pecentage score." Of course I can do this manually by hauling back on the slider while on the ground and raising it when enroute, but this is crude and, well, artificial. No one knows whether FSX contains improvements in traffic management (the emphasis on arcade play suggests pessimism) but let's not wait. Is there a talented utility creator out there?

[Guest RonB49]

That's a great idea and one that I'd never thought of. Saddly, I have no idea of how to implement it. R-

[jvile 1]

>>But no system is like thatIf you look at the original FP's that shipped with FS9 they look linear.Not only are all FP percentages randomized but, each type AI Plane is randomized against itself so a good mix of planes show at the airports. Now when you increase or decrease the slider you maintain the same mix but increase or decrease the amount of AI Planes proportionally.Many FP's that we download follow the MRAI (now closed) percent thought process that every FP must be set to 1 percent. How many look at their FP's and see what percent they are set at. If 1 percent is in all FP's the percent slider in FS9 is doing nothing and cannot control density like so many believe.

[Guest CowlFlapsOpen]

The randomization had the effect of equalizing the density across the range of percentages, which would explain why MS implmented it that way. Didn't know that. But the larger issue still stands: It would be nice to set a maximum AI density (or ceiling) for all this custom AI that is general across locations.

[tf51d 284]

For this to have any chance of working would depend on how FS reads the traffic.bgl file at startup. If it reads the whole file and keeps it in memory, but only displays ai flightplans above a specific percentage threshold,than this possibly could work, if that percentage could be adjusted on the fly. Probably using FSUIPC if that field is defined there. If however it filters flightplans not meeting this threshold out right at startup, (Which would be the more efficient way of doing it memory wise.) then I can't see how this could be done seamlessly, since you would have to reread the traffic.bgl file in constantly as you traverse from one area to another. Which as you know could be quite large.

[Guest CowlFlapsOpen]

This is the type of thing Reggie Fields can answer definitively off the top of his head, but I understand that FS already contiously activates and deactivates flight plans in a generous radius around the aircraft.

[mnmon 0]

The real issue, for me, with regard to AI traffic is not the percentage that is generated but the manner in which FS spawns the traffic and controls its movements. Busy airports are the worst in which every AI plane scrambles to the runway creating ridculous conga lines even compared to the real world situation. The most annoying aspect is the cases where 3 planes are within a 1/2 mile of each other all trying to land on the same runway. AISmooth etc, have helped, but I'm hoping FSX will do something about this, but I haven't seen any indication that this has been addressed :-( Mike

[Guest Loiosh]

The official statement on this is just bug fixes. There will be no improvements otherwise to the AI Traffic situation. I use FS Live Traffic (as real as it gets =) ) with AI Smooth to manage all of my traffic. Sometimes it gets pretty crazy at KDFW.

[tf51d 284]

> The real issue, for me, with regard to AI traffic is not>the percentage that is generated but the manner in which FS>spawns the traffic and controls its movements. Busy airports>are the worst in which every AI plane scrambles to the runway>creating ridculous conga lines even compared to the real world>situation. The most annoying aspect is the cases where 3>planes are within a 1/2 mile of each other all trying to land>on the same runway. AISmooth etc, have helped, but I'm hoping>FSX will do something about this, but I haven't seen any>indication that this has been addressed :-(>>> Mike>The problem with the mad dash can be mitigated with time. When you start FS The AI engine doesn't just spawn flights from that time on, it activates flights from about 30 min+ before. This means in addition to the schedule flights at that time, you have all the flights that were within that window, trying to leave (and land) at the same time. Once they're gone things do settle down a bit, but that could take a while. An easy fix they could do in FSX if they're not going to overhaul the whole AI engine, (Which I think is much more needed then things like missions!! But that's just my personal opinion!) would be to activate only flights that are scheduled to land and depart after the start time of your flight!

[Guest RonB49]

Along with using AISmooth, I found that increasing the AI's landing rollout speed and taxi speed reduced traffic congestion greatly. One of Ken Salter's programs (FS Configurator, I think) provides the means to adjust those speeds. If parallel runways exist, then using AFCAD2 to assign one runway to landing and another runway to takeoffs also cushions the imact of high AI traffic loads. R-

[RFields5421 1]

Jim Vile did much of the research where I learned.However, FS reads all the traffic files and figures out where all the AI traffic belongs at X time and day which is current in your FS world.It then loads the aircraft which are supposed to be in the local area - which varies but can be up to 108 miles in radious, and can be as small as 35 miles which I've seen.There is some impact upon aircraft generation for slower moving smaller aircraft - them being created closer to the destination airport than the jets.The largest impact is the creation process for flight plans as Jim noted above.Basically, if you don't use a commercial product, or PAI - you have no option to use the AI slider at most of your airports.Almost all of the beautiful, "realistic", "100% accurate" flightplans on this, and other websites make the AI slider useless.Until flight planners get out of their head that everyone has to run ALL their flight plans - .....However, back to the basic concept - sounds interesting - though I have no idea how or if it could be implemented.Possibly something like FS Live Traffic could work.

[mnmon 0]

I've implemented just about every tweak that can be done: assigned parallel runways as either exclusive T/O or Landing in AFCAD, (doesn't work in places like LaGuardia). etc. The real key is what was suggested above: have FS spawn flights only from the time of start forward. Seems like a one line of code fix. Maybe FSUIPC could be used in some way to help. Mike

[Max Kraus 338]

I'm a stubborn 100% or nothing man. I should really drop it to 0% on approach and then put it back to 100% after I roll off the runway.I like your idea though!

[Guest CowlFlapsOpen]

ah, yes, one of the 100% men. some of us can only dream...

[Guest MD11Forever]

The "conga lines" and mass AI arrivals can be reduced by simply firing up the sim and waiting for 15-20 minutes "actual" time to pass. Use that time to check weather, charts, etc...or just go grab a sandwich. Couple this method with a program like AISmooth and I rarely, if ever, see a squadron of aircraft on finals or wait for more than a few planes to depart in front of me. And yes, I'm a "100 percent-er". :-wave