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Trade Range Increase For Bigger Maps

Version 2: New method of extending trade route range on Large and Huge, Tech Tree should no longer be bugged.

Requires BNW, of course.

Increases land and sea trade route maximum range by approximately 24% on Large Maps and approximately 54% on Huge Maps. First, you must know the formula the game uses for determining maximum trade route range: MaxRange = (BaseRange + TechTrue)*(1+PercentIncrease), rounded down (note: parameter names are not real I just made them up).
BaseRange:10 for non-Arabian caravans, 15 for Arabian caravans and 20 for cargo ships.
TechTrue refers to additional range based on techs discovered: 10 for caravans if Combustion is researched, 10 for cargo ships if Compass (but not Refrigeration) is researched, 20 for cargo ships if Refrigeration is researched (Refrigeration gives 10, but since its prerequisite is Compass, the total value is 20), 0 otherwise.
PercentIncrease refers to the bonus range caravansaries/harbors give to land/sea trade routes respectively, which is 0.5 in the unmodded game if you've built them and 0 if not.

I made a hidden building which is provided for free to cities when they are created, which acts as a caravansary and harbor combined, having a PercentIncrease value of 0.24 on Large Maps and 0.54 on Huge Maps, increasing range by 24% and 54% before a caravansary/harbor is built. Then, I buffed the multiplier of caravansaries/harbors to 62% and 77% on Large and Huge Maps respectively, maintaining the +24% and +54% after they are built. (The effects of multiple caravansary-type buildings stack additively, thus for example on Huge Maps the new PercentIncrease after a caravansary/harbor is built is 0.54+0.77=1.31, and the total multiplier, 2.31, is 54% more than in the base game, 1.5, for a city with a caranvasary/harbor.)

The changes to all combinations of trade route maximum range can be found in this spreadsheet[docs.google.com], the fields labelled 'Standard or smaller' indicating unmodded game values. Note that this just shows the displayed range in the trade screen, in reality the actual range of land trade routes can be extended by roads (see this[civilization.wikia.com]).

This mod probably doesn't work with other trade route extending mods in general, and will not work with other mods which make changes to the default caravansary/harbor (e.g. changing their values, having a unique caravansary/harbor), since this mod essentially replaces the default one with a completely new, buffed one on Large/Huge Maps. However it does work with my other mods. Of course, on Standard and smaller maps, this mod essentially has no effect, so they will work together, but if you're playing on standard or smaller maps you wouldn't even turn this on.

I wanted to nerf the range on smaller-than-Standard size maps so this mod makes trade range truly balanced with map size, but they won't let me put negative values for the hidden building....

KNOWN BUGS (Version 2 resolved): In the technology tree/research progress, you'll see the versions of caravansaries/harbors which are NOT going to be unlocked when Horseback Riding/Compass is researched. Don't worry, the actual one unlocked will be the right version. There are no hidden tech unlocks for hidden techs for Horseback Riding, but there are 2 for Compass: "Allows establishing an additional trade route." and "Extends the range of sea trade routes." Sorry I don't know how to fix, but if I do I'll update.