AI traffic can reduce FPS in Microsoft Flight Simulator. Learn which aircraft, ground and airport traffic settings to lower first.
Yes. AI and live traffic can reduce FPS in Microsoft Flight Simulator, especially at busy airports, because every aircraft adds simulation logic, model, lighting and draw-call work, much of it on the main thread. Lower Ground Aircraft Density first, then reduce airborne traffic, airport vehicles and workers, and remove duplicate traffic sources.
The effect is greatest at large hubs, during approaches and whenever many aircraft are visible. Traffic may barely affect FPS over an empty rural area, so test at the sort of airport where you normally experience stutters.
Which MSFS traffic settings should I lower first?
Lower parked aircraft and airport activity before sacrificing all airborne traffic. Microsoft Flight Simulator 2020 and 2024 use similar traffic controls, although their location and wording can vary by platform and update; search the simulator settings for Traffic if necessary.
| Setting | Recommended first change | What it affects |
|---|---|---|
| Ground Aircraft Density | Set it to the minimum for testing, then raise it gradually. | Stock parked aircraft at gates and stands. These add models, textures, lights and draw calls and can duplicate injector-supplied aircraft. |
| Aircraft Traffic Type | Select Off for a baseline. Re-enable either Live or offline AI if wanted. | The simulator's airborne traffic source. Leave it off when an external injector supplies traffic. |
| AI Traffic Density | Reduce it if the option is available in offline AI mode. | The number of active AI aircraft. It may not control Live Traffic. |
| Airport Vehicle Density and Worker Density | Use low settings at detailed airports. | Service vehicles and animated staff around gates, aprons and terminals. |
| Road Vehicles | Lower it near large cities or airports surrounded by roads. | Moving road traffic, which is separate from aircraft traffic but still consumes CPU and rendering resources. |
| Ships and Ferries and Leisure Boats | Reduce them when flying around busy coastlines. | Marine traffic. It usually matters less at inland airports. |
| Generic AI aircraft models | Enable them if offered and exact aircraft models are not essential. | Simpler models may ease GPU and memory pressure, but they do not reduce the number of simulated aircraft. |
A mistake we see constantly is treating Ground Aircraft Density as the control for moving live flights. It mainly fills parking positions. Turning it down can clear a crowded apron while airborne traffic remains unchanged; conversely, switching Aircraft Traffic Type off can still leave stock parked aircraft, multiplayer pilots or injector traffic visible.
Three practical traffic profiles
Use one traffic source at a time, then spend the remaining performance budget on the activity you care about most.
- Maximum FPS: Disable simulator AI or live traffic, minimise Ground Aircraft Density, airport vehicles, workers, road traffic and marine traffic, and disable multiplayer during controlled tests.
- Balanced live traffic: Enable Live Traffic, keep parked aircraft and airport activity low, and do not run a separate injector simultaneously. Our guide to setting up real-world traffic in MSFS 2020 without duplicates explains the relevant traffic options in more detail.
- External traffic injector: Turn the simulator's own aircraft traffic off and begin with Ground Aircraft Density at zero. Control active or IFR aircraft, injection radius and parked aircraft inside the injector; our comparison of AI traffic injector controls identifies the limits that matter most for performance.
If an injector does not supply parked aircraft, you can add a small amount of stock ground traffic afterwards. Watch for duplicate aircraft, occupied gates and airliners using unsuitable stands.
How should I test traffic performance?
Test one traffic source and one setting at a time at the same busy airport. Changing everything together makes it impossible to identify the expensive option.
- Create a clean baseline: Turn off in-simulator traffic, close any injector, minimise parked aircraft and temporarily disable multiplayer.
- Reload the flight: Existing aircraft may not disappear immediately after a setting change. Returning to the menu and loading the same gate gives a cleaner comparison.
- Check the limiting component: On PC, use the simulator's FPS display if available. A MainThread limitation is the strongest sign that reducing active traffic may help; a GPU limitation points more towards resolution, clouds, shadows or complex aircraft models.
- Enable one traffic source: Choose Live Traffic, offline AI or an injector, never several at once.
- Add density gradually: Increase parked aircraft and airport activity until the visual improvement no longer justifies the frame-time cost.
- Test an arrival: A departure from an empty gate is not enough. Check the setup on approach to a busy airport, where traffic, scenery and cockpit systems compete for resources.
Does live traffic reduce FPS as well?
Yes; live traffic creates the same types of local rendering and simulation cost once aircraft are spawned. Its real-world data source does not make the resulting models free to render, and performance can vary with the airport and time because the aircraft count is less predictable.
If Live Traffic produces no aircraft at all after you re-enable it, treat that as a separate data, connectivity or configuration fault and use our live-traffic troubleshooting checks.
Why did lowering traffic not increase FPS?
A traffic reduction only raises FPS when traffic was part of the bottleneck. Several common conditions can hide the improvement:
- The simulator is GPU-limited: Fewer aircraft may reduce stutters without materially changing the FPS counter. Lower GPU-heavy graphics options instead; our broader MSFS 2024 performance checklist covers the main alternatives.
- Another traffic source remains active: Multiplayer aircraft and external injector traffic are not necessarily controlled by Aircraft Traffic Type.
- Your frame rate is capped: FPS will not rise past the cap, although reduced traffic can still provide steadier frame times and more performance headroom.
- Old traffic has not cleared: Reload the flight before judging a large setting change.
- The test area is too quiet: Traffic adjustments show their value at congested hubs, not over sparsely populated terrain.
For most systems, the sensible compromise is low parked-aircraft and airport-activity density with one airborne traffic source. If the simulator is still main-thread limited at a busy hub, reduce the active aircraft count or injection radius rather than stripping away unrelated graphics quality.