Traffic Settings Explained
Estimated Lesson Time: 45–55 Minutes
Lesson Overview
Throughout Module 3, we’ve explored how graphics settings affect both image quality and performance.
Today we’re going to focus on one of the largest performance categories in Microsoft Flight Simulator:
Traffic.
Traffic brings the simulator to life.
You’ll see:
- Airliners taxiing.
- Aircraft taking off.
- Aircraft landing.
- Ground vehicles moving.
- Airport workers.
- Cars driving on roads.
- Ships crossing oceans.
- Boats travelling along rivers.
- Wildlife throughout the world.
While these features greatly improve immersion…
Every moving object requires additional processing.
Understanding which traffic settings affect the CPU, GPU and RAM will allow you to optimise performance without making the simulator feel empty.
Lesson Objectives
By the end of this lesson you will understand:
How AI Traffic works.
How Live Traffic works.
How Ground Aircraft affect performance.
How Airport Workers affect the simulator.
How Road Traffic impacts the CPU.
How Ships and Boats affect performance.
How Fauna affects performance.
Which traffic settings affect the CPU.
Which traffic settings affect the GPU.
Which traffic settings increase RAM usage.
1. What Are Traffic Settings?
Traffic settings control all of the moving objects within Microsoft Flight Simulator.
Unlike buildings or scenery…
Traffic is dynamic.
Every vehicle…
Every aircraft…
Every animal…
must constantly update its position.
The simulator continuously calculates:
Movement.
Navigation.
Collisions.
Animations.
Lighting.
Visibility.
This places additional demand on your PC.
2. AI Traffic
AI Traffic creates computer-controlled aircraft that fly around the simulator.
These aircraft:
Taxi.
Take off.
Climb.
Cruise.
Descend.
Land.
Taxi to gates.
Every AI aircraft behaves independently.
Why AI Traffic Is CPU Intensive
Each aircraft constantly calculates:
Navigation.
Flight plan.
Taxi routing.
Aircraft systems.
Collision avoidance.
Runway separation.
ATC interaction.
This work is performed primarily by the CPU.
The GPU simply renders the aircraft.
Performance Impact
CPU:
★★★★★ Very High
GPU:
★★★☆☆ Moderate
RAM:
★★★☆☆ Moderate
3. Live Traffic
Live Traffic attempts to represent real-world aircraft movements.
Instead of random aircraft…
The simulator downloads live traffic information and recreates flights in real time.
Live Traffic can greatly increase immersion at major airports.
Why Live Traffic Is Demanding
Each aircraft still requires:
Navigation.
Movement.
Rendering.
Lighting.
Animations.
Although the traffic source is different, the performance characteristics are similar to AI Traffic.
Performance Impact
CPU:
★★★★★ Very High
GPU:
★★★☆☆ Moderate
RAM:
★★★☆☆ Moderate
4. Ground Aircraft
Ground Aircraft are parked aircraft placed around airports.
Unlike AI aircraft…
They do not move.
However…
Every parked aircraft still contains:
3D models.
Textures.
Shadows.
Reflections.
Lighting.
The GPU must render every one of them.
Performance Impact
CPU:
★★☆☆☆ Low–Moderate
GPU:
★★★★☆ High
RAM:
★★★☆☆ Moderate
5. Airport Workers
Airport workers include:
Marshals.
Ramp staff.
Fuel operators.
Maintenance engineers.
Baggage handlers.
Each worker contains:
Animations.
Movement.
Lighting.
Shadows.
The CPU constantly updates their animations while the GPU renders them.
Performance Impact
CPU:
★★★☆☆ Moderate
GPU:
★★☆☆☆ Low–Moderate
RAM:
★★☆☆☆ Low
6. Road Traffic
Road Traffic includes:
Cars.
Lorries.
Buses.
Emergency vehicles.
Motorcycles.
Unlike static scenery…
Every vehicle moves independently.
The simulator constantly calculates:
Road routing.
Traffic flow.
Speed.
Lighting.
Animations.
This makes Road Traffic surprisingly CPU intensive.
Performance Impact
CPU:
★★★★☆ High
GPU:
★★☆☆☆ Moderate
RAM:
★★☆☆☆ Low
7. Ships & Boats
Water traffic includes:
Cargo ships.
Cruise ships.
Fishing boats.
Pleasure boats.
Ferries.
Tankers.
These vessels move around coastlines and waterways.
Although there are usually fewer ships than cars…
Each vessel still requires:
Movement.
Lighting.
Animation.
Rendering.
Performance Impact
CPU:
★★☆☆☆ Low–Moderate
GPU:
★★☆☆☆ Low–Moderate
RAM:
★☆☆☆☆ Very Low
8. Fauna
Fauna includes:
Birds.
Animals.
Wildlife.
Marine life (where supported).
Although visually interesting…
These objects are usually less demanding than aircraft or vehicles.
Performance Impact
CPU:
★★☆☆☆ Low
GPU:
★★☆☆☆ Low
RAM:
★☆☆☆☆ Very Low
9. Why Traffic Is So Demanding
Imagine arriving at Heathrow.
The simulator may be managing:
120 AI aircraft.
300 ground vehicles.
Thousands of airport workers.
Hundreds of parked aircraft.
Thousands of road vehicles.
All at the same time.
Every one of these objects updates continuously.
This is why traffic is one of the biggest causes of MainThread limitations.
10. CPU vs GPU vs RAM
Let’s compare the major traffic settings.
|
Setting |
CPU |
GPU |
RAM |
|---|---|---|---|
|
AI Traffic |
|
|
|
|
Live Traffic |
|
|
|
|
Ground Aircraft |
|
|
|
|
Airport Workers |
|
|
|
|
Road Traffic |
|
|
|
|
Ships & Boats |
|
|
|
|
Fauna |
|
|
11. Which Settings Affect The CPU Most?
The biggest CPU settings are:
AI Traffic.
Live Traffic.
Road Traffic.
Airport Workers.
Ground vehicle density.
These settings increase MainThread workload because the CPU must constantly update movement and behaviour.
12. Which Settings Affect The GPU Most?
The biggest GPU traffic settings are:
Ground Aircraft.
Large numbers of AI aircraft.
Aircraft shadows.
Aircraft reflections.
These require the graphics card to render more models and textures.
13. Which Settings Increase RAM Usage?
RAM stores:
Aircraft models.
Textures.
Animations.
Traffic information.
The largest RAM users are:
AI Traffic.
Live Traffic.
Ground Aircraft.
Large airports with many objects.
More RAM allows the simulator to keep more of this information readily available without relying as heavily on storage.
14. Optimising Traffic
If you’re CPU limited…
Reduce:
- AI Traffic.
- Live Traffic density.
- Road Traffic.
- Airport Workers.
- Ground Vehicles.
If you’re GPU limited…
Reduce:
- Ground Aircraft.
- Static Aircraft.
- Aircraft shadows.
- Reflection quality.
If you’re running low on memory…
Reduce:
- Traffic density.
- Ground Aircraft.
- AI aircraft.
- Large traffic add-ons.
15. Common Myths
Myth 1
“Traffic only affects the GPU.”
False.
Most traffic calculations are performed by the CPU.
Myth 2
“Road Traffic has almost no impact.”
False.
Road Traffic can create significant CPU workload, particularly in large cities.
Myth 3
“Ground Aircraft are free.”
False.
Every parked aircraft must still be rendered and stored in memory.
Myth 4
“More RAM always gives more FPS.”
False.
Additional RAM can reduce stutters caused by memory pressure, but FPS is still largely determined by CPU and GPU performance.
Student Exercise
Today we’re going to compare Traffic settings.
Step 1
Load your Module 1 benchmark flight.
Use:
- Same airport.
- Same aircraft.
- Same weather.
Choose a large international airport for the most meaningful comparison.
Step 2
Compare:
- AI Traffic.
- Live Traffic.
- Ground Aircraft.
- Road Traffic.
- Airport Workers.
Step 3
During each test, record:
- Average FPS.
- Lowest FPS.
- MainThread status.
- CPU utilisation.
- GPU utilisation.
- RAM usage.
- Airport realism.
- Overall smoothness.
Step 4
Compare the results.
Ask yourself:
- Which traffic setting had the biggest impact on CPU performance?
- Which had the greatest effect on GPU usage?
- Which settings increased RAM usage the most?
- Which settings added meaningful realism?
- Which could be reduced without noticeably affecting your experience?
Student Checklist
AI Traffic tested.
Live Traffic compared.
Ground Aircraft evaluated.
Road Traffic reviewed.
Airport Workers compared.
CPU usage monitored.
GPU usage monitored.
RAM usage recorded.
Best traffic settings selected.
Lesson Summary
Congratulations.
You now understand one of the most important performance categories in Microsoft Flight Simulator.
Remember:
- Traffic settings bring the simulator to life but can significantly increase system workload.
- AI Traffic and Live Traffic are among the most CPU-intensive features because every aircraft continuously calculates navigation, movement and behaviour.
- Ground Aircraft primarily increase GPU and VRAM usage by adding more models and textures to render.
- Airport Workers and Road Traffic add realism but also increase CPU workload through animations and pathfinding.
- Ships, Boats and Fauna generally have a smaller performance impact but still contribute to overall system load.
- The best traffic settings depend on your hardware and the type of flying you enjoy.
- If you’re MainThread limited, reducing AI Traffic and Road Traffic can often produce larger improvements than lowering purely graphical settings.