Yes, compared to the previous game, there's one larger map size available, which is indeed called "Very Large".
Map sizes are Small (8x8 km), Medium (12x12 km), Large (14x14 km) and Very Large (16x16 km). At ratios 1:2 and 1:3, very large clocks in at 11x22 km or 9x27 km.
I have the feeling that large is the same size as in the previous game, so the new "very large" option is only 25% larger in area. Still, it feels sufficiently huge for my tastes.


Oh, or reading your question again: Maybe you're asking if you can go even larger than "Very Large"? In that case, obviously not through the interface, and I can't immediately find anything in the (very readable) lua config files either, though I imagine that if it is possible, someone in the modding community should know.

Of course, have a look over here:

https://youtu.be/QzEsygQoFgs

On GOG-Version u can find settings.lua via:

%appdata%\Transport Fever 2

Copy and past it in taskbar in explorer.

On linux:

https://www.transportfever.net/lexikon/index.php/Entry/276-Verzeichnispfade-f%C3%BCr-Linux/

Its german but u can understand this pathes anyway where it belongs.

Set "Experimental Map sizes = true" in the settings. Then you can play megalomaniac maps (24x24km). Do not expect any performance!