Transport Fever 3 Bigger Maps: Unlock Huge Map Sizes

By Tobias Lindqvist · Updated October 1, 2026

Which map sizes Transport Fever 3 offers

When you start a Free Game, the map size dropdown in the World section has four choices: Small, Medium, Large and Very Large. Four more sizes exist in the game files but are hidden behind an experimental switch: Tiny, Huge, Megalomaniac and Gigantomaniac. You can also pick a map format, which is the ratio between the two edges, from 1:1 up to 1:5.

On PlayStation 5 and Xbox Series X|S, the official wiki says memory limits restrict you to Small, Medium and Large. Very Large and every experimental size are PC and Mac only. More on that on our console page.

Map size table

All figures below come from the Map Sizes page of the official Transport Fever 3 wiki. Sizes marked “exp.” need the settings.lua change described in the next section. The wiki notes that the in-game menu rounds these numbers, so what you see may differ by up to 250 m.

In area terms, a square Gigantomaniac map covers a little over three times the ground of a square Very Large map. One small oddity: the wiki lists identical numbers for Tiny at 1:3 and 1:4 (2,048 x 6,144 m). That looks like a typo on the source page, so check the in-game value if you need Tiny at 1:4.

How to unlock the experimental map sizes

These steps follow the official wiki’s “Enable Experimental Map Features” section. The Flowengineer “50+ tips” video (September 29, 2026) shows the same method, and three of the eight Steam community guides that existed on October 1 cover it too.

1. Quit the game completely. The wiki asks you to close it before editing, and the settings page says this file can only be changed while the game is not running.
2. Open your userdata folder. The quickest route is Settings, then the Advanced tab, then the Open User Data Folder button. The manual and the Flowengineer video both point to that button. If you would rather browse to it, our save file location guide lists the path for Steam, GOG and Epic on each operating system.
3. Open settings.lua in a plain text editor. The keys are usually sorted alphabetically, so look near the top under “e”.
4. Find experimentalMapFeatures and change its value to true. The line should end up like this:

function data()
return {
  ...
  experimentalMapFeatures = true,
  ...
}
end

5. Save the file and start the game again. The extra sizes now appear in the Map Size dropdown for new Free Games and in the Map Editor.

If you edit the file and the game refuses to start or your settings look broken, the troubleshooting page says you can delete settings.lua to go back to defaults. You will lose your graphics and key settings, so keep a copy of the file first.

What else the flag changes

The same switch also lets you change the economy of an existing savegame. The official wiki warns this “might lead to unstable situations”, so treat it as a test feature and keep a backup save before you try it. The settings reference table describes experimentalMapFeatures the same way: experimental map sizes plus economy changes for existing saves. Nothing else is listed.

Map size, format and climate are fixed once a map exists. The Map Editor page states you cannot change any of the three inside the editor, so pick your size before you press Start.

Performance warning before you go big

Bigger is not free. The official wiki ties map size to RAM use and, in most cases, CPU load, and says experimental sizes need at least 16 GB of RAM. The minimum PC spec on Steam is 8 GB, so a minimum-spec machine falls short of what these maps need. Compare your hardware on our PC requirements page.

A few other points from the official manual:

• Generating a new map takes longer as size grows, and also depends on how many towns and industries you asked for.
• The Population slider in Advanced gameplay settings directly affects simulation performance.
• Towns placed close together cost more CPU than fewer, spread-out towns, because every resident has more possible destinations to path to.
• If speeding the game up to 2x or 4x does not make it faster, your CPU is the limit, and lowering graphics will not help much.

For a real-world reference point, Flowengineer says in the same video that a total map population of around 40,000 was the smooth ceiling on his machine. That is one player’s hardware, not an official limit. If a huge map starts to crawl, see our performance fix guide.

Importing heightmaps for large maps

If you want a real-world area at Huge size or above, the Map Editor imports grayscale PNG heightmaps. Each pixel stands for a 4 x 4 m square, which is why a 1025-pixel image becomes a 4,096 m map. The editor page recommends 16-bit grayscale and reads files from the heightmaps folder inside userdata. Use the pixel sizes in the table above so the image matches the map exactly.

Map seeds: how to get the same map again

Every generated map comes from a seed, a value the generator uses as its randomization key. The official manual is explicit that the same seed with the same settings produces an identical map every time. That has two practical uses:

• Share a map. Note the seed and every setting (size, ratio, climate, generator sliders) and another player can rebuild the same terrain.
• Re-roll terrain. If a start position is bad, change only the seed and keep the rest of your settings.

In the map editor the seed box sits at the bottom of the generator settings, and the automatic town distribution tool has its own seed box, so you can keep the terrain and re-roll only where towns land. Modded terrain generators from the Mod Hub bring their own options, so a seed is only reproducible with the same generator mod installed. We have not found an official or tested list of “best seeds”, so none is given here.

Sources for each step

• Size list, table values, the settings.lua key, the 16 GB note and the console limit: official wiki, Map Sizes page.
• Open User Data Folder button and the “game must be closed” rule: official wiki, Settings page.
• Editor limits and heightmap format: official wiki, Map Editor page.
• The 40,000 population anecdote: Flowengineer video, a single player’s report.
• Seed behaviour: official wiki, Free Game and Map Editor pages.