PlayTrail Guide

Transport Fever 3 Experimental Map Sizes: Enable and Undo

Locate the Windows Steam settings file, enable experimental map sizes, and restore the original setting if the map is too demanding.

Last checked

Original concept illustration of a transport network; not gameplay footageOriginal concept art; not a screenshot of the experimental map menu.

Transport Fever 3 hides its experimental map sizes behind a setting in the Windows Steam user-data file. Community map makers report using this switch on the release branch. It is an experimental feature, not a promise that a larger map will run well on every computer.

Enable the map options

  1. Close the game completely before changing the file.
  2. Locate the Steam user-data folder for Transport Fever 3. A common Windows path is Steamuserdata<your Steam ID>3493540localsettings.lua. The Steam folder need not be under Program Files; use the installation's actual location. If the game offers an Open User Data Folder button under Settings and Advanced, use it to confirm the directory.
  3. Copy settings.lua to a backup file outside the game folder.
  4. Open the original in a plain-text editor. Find experimentalMapFeatures = false, and change only false to true. Keep the comma and the rest of the line unchanged.
  5. Save, restart the game, and check the map-size choices when creating a new Free Game. This setting does not resize an existing save.

If the option is missing or the game will not start

Check that this is the settings file under app ID 3493540, not a Transport Fever 2 file or another Steam account's folder. Confirm that the game was closed when the file was edited and that the line still ends with a comma. If the file cannot be found, do not create an invented one; locate the game's user-data directory first.

To undo the change, close the game and restore the backed-up settings.lua, or change the same value back to false. If the file was damaged, restoring the untouched backup is safer than guessing other settings.

Before choosing the largest map

The developer warns that large or heavily developed maps increase simulation work and may reduce performance, especially with many cities, vehicles and complex networks. Start a separate new game and keep the original save. This guide covers Windows Steam only; it has not independently checked the key on console, Epic, GOG, macOS or Linux.

Version note

The official PC notes list Steam build 40408 as the stable initial release and later 40420 as a preview build. Community reports support this procedure around the stable release; preview behavior and future updates may differ. Last checked 8 October 2026.