Quick answer
First work out what is slowing you down. Pause the game: if FPS is still low while paused, your graphics card is the limit, so lower resolution, anti-aliasing, shadows, textures and detail.[1] If raising speed to 2× or 4× barely speeds up the simulation, your CPU is the limit. Lowering graphics "usually has little effect" there, so use a smaller map or a less dense network instead.[1][2]
GPU-bound: FPS low even when paused
The official known-issues page recommends reducing:[1]
- resolution
- anti-aliasing
- shadow quality
- texture quality
- level of detail and other GPU-heavy effects
Playing at 1920×1080 instead of 3840×2160 "can significantly reduce GPU load". On laptops or PCs with two GPUs, make sure the game runs on the dedicated card.[1] The settings menu also has a Resolution Scale to lower the rendering resolution of the main view.[3]
CPU-bound: 2×/4× speed doesn't help
The simulation load grows with the map and the network. It rises with many cities, dense networks, many vehicles, complex road traffic, many industries and cargo links, and large mods.[1] Transport Fever 3 simulates every resident's trips between home, work and shopping, so large cities and many towns close together get heavy.[2] What helps:
- Smaller maps: the manual notes that "Smaller maps tend to run more fluently on most computers" (map sizes).[4]
- Fewer or lighter mods
- Closing background applications. Low system memory is also listed as a cause.[1]
Low VRAM
If your card has little video memory, lowering texture quality and disabling high-resolution texture mods without LODs can raise FPS a lot, according to the troubleshooting page.[2]
The four graphics presets
| Setting | Low | Medium | High | Very High |
|---|---|---|---|---|
| Textures | Low | High | High | Very High |
| Terrain textures | Low | High | High | Very High |
| Anti-aliasing | Off | 2× | 4× | 4× |
| Ambient occlusion (SSAO) | Off | On | On | On |
| Reflections (SSR) | Off | Medium | High | High |
| Geometry | Low | Medium | High | High |
| Shadows | Low | Medium | High | High |
| Terrain | Low | Medium | High | High |
| Grass | Off | Medium | High | High |
Source: official settings page.[3] Reading the table: the jump from Low to Medium is the biggest one. It switches on SSAO, reflections and grass and raises textures straight to High. The official page also calls visualization "one of the performance bottlenecks".[3] If you are close to the minimum specs, start from Low and raise one setting at a time.
Meeting the requirements isn't a guarantee
The official known-issues page says meeting the minimum requirements "does not guarantee high frame rates in every situation". Big, developed saves are the main reason.[1]
Steam Deck and consoles
There is no official Steam Deck rating yet (system requirements). A PS5 reviewer reported "No frame rate stutters or graphical issues either" in their playthrough. That is one reviewer's experience, not a benchmark.[5]