FSX road traffic missing? Restore cars and lorries by checking the Road Vehicles slider, scenery coverage, add-on conflicts and FSX.cfg.
Road traffic is usually missing in FSX or FSX: Steam Edition because the Road Vehicles density slider is set to zero, the visible road has no traffic-enabled path, or add-on scenery has replaced the default road data. Raise the slider first, then test an untouched default-scenery area.
How do I restore missing road traffic in FSX?
Use the following order so that you can distinguish a global traffic setting from a problem affecting one scenery area.
- Open the Traffic settings. Open Settings, select Display, then the Traffic tab. Find Road Vehicles under land and sea traffic. Airline traffic, general aviation traffic and airport vehicle density control different types of movement.
- Raise Road Vehicles temporarily. Start at 50%; if no cars appear, use 100% as a diagnostic setting. Apply the change and reload the flight if traffic does not populate immediately.
- Test a suitable default road. Use a major motorway or urban road in an area with unmodified default scenery. Small streets, roads painted into aerial imagery and many airport access roads may not have traffic paths.
- Compare another region. If vehicles appear elsewhere, the global setting works and the original location has missing, excluded or unsupported road data.
- Disable the local add-on temporarily. Untick every Scenery Library entry belonging to that area, restart FSX and repeat the test. If default traffic returns, the add-on is replacing or excluding the relevant road network.
| What you see | Likely cause | Best next check |
|---|---|---|
| No road vehicles anywhere | Road Vehicles is zero, the configuration is not saving, or stock scenery data is damaged | Check the slider and FSX.cfg |
| Traffic is missing only around one add-on | Road exclusions or replacement vector scenery | Disable that scenery area and restart FSX |
| Cars appear only at high density | The route is sparsely populated at lower percentages | Choose the lowest density that remains visible |
| Airport tugs appear but public-road cars do not | Airport and road vehicles use separate settings | Adjust Road Vehicles, not airport vehicle density |
What if Road Vehicles keeps returning to zero?
A Road Vehicles slider that will not retain its value usually points to an FSX configuration problem. Close the simulator before inspecting the file because FSX can overwrite manual changes when it exits.
Boxed FSX normally stores the configuration at %APPDATA%\Microsoft\FSX\fsx.cfg. Steam Edition commonly uses %APPDATA%\Microsoft\FSX-SE\fsx.cfg, although installation history can affect which profile folder is active. The road-traffic value is stored as FreewayDensity under [TrafficManager].
Back up the file, make sure it is not read-only, and confirm that FreewayDensity is not zero. If settings still refuse to save, rename fsx.cfg and launch FSX so it builds a clean one. This resets simulator preferences and tweaks; if the fresh file works, reapply settings manually rather than copying the entire old configuration back.
If traffic remains absent globally with a fresh configuration and default scenery, verify the installed files in FSX: Steam Edition. For boxed FSX, use the installer's repair option. Back up any modifications made directly to stock folders first.
Why do cars appear on only some FSX roads?
FSX displays cars and lorries only on roads with traffic-enabled route data, not on every road visible in the scenery. A road printed into a photoscenery texture can look convincing from the air while having no underlying path for moving vehicles.
Low density settings also produce uneven results: one motorway may be busy while a nearby route appears empty. Raising the slider to 100% helps identify this. For example, our Portsmouth scenery notes on intermittent default road traffic document a case where maximum road density can restore vehicles.
Can add-on scenery remove FSX road traffic?
Yes—add-on scenery can exclude default roads to prevent duplicate or misplaced traffic, then replace them with roads that lack traffic paths. Other packages provide a separate animated-traffic BGL which stops working if that file is disabled, renamed or omitted during installation.
The documentation for the RAF Woodvale package's separate animated-traffic file illustrates how custom road movement can be supplied independently of other scenery files. Do not delete every BGL containing “traffic” in its name; aircraft, ships and unrelated scenery may use separate traffic databases. Disable the suspect scenery entry or only the package-specific file identified by its documentation.
Does FSX road traffic reduce FPS?
Yes, dense road traffic can reduce FSX performance because the simulator must draw and update many moving vehicles. We recommend using 100% only for diagnosis, then reducing it to the lowest level that still gives acceptable activity.
For busy urban scenery, Road Vehicles is often one of the first traffic options to trim. Our guide to FSX settings that trade visual activity for frame rate explains how to balance this slider against AI traffic, scenery and autogen without hiding more than necessary.