So, without the additional effects lent by roads or weather, one may gather some general ideas about supply distribution under the new supply rules.
1. Non playable hexes can't be entered by a unit, but supply reduction occurs within them (see second image above).
2. Alpine, dunes, flooded marsh, and badlands block supply distribution (supply value = 0 in those hexes). Likewise, "super" river, major escarpment hexsides, and Suez Canal terrain blocks supply distribution.
3. Supply distribution over open and arid terrain will occur quite freely unless the supply radius is set to a low value.
In terms of roughly comparing terrain effects on supply distribution, one way to look at it is to see how many hexes of a given terrain type cause the supply value to drop to roughly half, as compared to a fully supplied hex. In cases where the fully supplied hex is at the value of 110, these figures show how many hexes supply distribution occurs through before the supply value of the hex drops to 51. Besides terrain which blocks supply distribution, there are four classes of terrain:
Most restrictive (mountain, marsh, jungle, minor escarpment hexside)
Restrictive (forest, hills, hedgerow, rocky)
Less restrictive (sand, light woods, cropland, dense urban)
Least restrictive (open, arid, urban)
Because the supply value depends on the force supply stockpile and the supply radius setting, the number of hexes to drop from a supply value of 110 to 51 is variable. In the case of the supply radius being set to 5,
Most restrictive -- 3 hexes
Restrictive -- 4 hexes
Less restrictive -- 6 hexes
Least restrictive -- 12 hexes
Now look the number of hexes if the supply radius is doubled to 10:
Most restrictive -- 6 hexes
Restrictive -- 8 hexes
Less restrictive -- 12 hexes
Least restrictive -- 24 hexes
Which indicates the effect of the formula that takes into account motorized movement rate and the supply radius setting. It is a relationship of 3:4:6:12 for the four classes of terrain.
Bear in mind this is all "in general" and can widely vary because of the effects like the improved road divisor or weather effects.
