Effect of rubble and mines on local supply?

[Mowgli]

Im my recent Scheldt '44 match, I started to wonder about rubble and mines and how they affect local supply. 
I ran some tests in the scenario 1016 Venraij and the results left me somewhat confused: 

RUBBLE

1) If you control a road INTO a rubble hex, local supply seems to be totally unaffected by rubble (this seems to disagree with the manual which states that roads cannot be used into/out of (?) rubble hexes). 
2) If you do not control a road into a rubble hex, then rubble does affect your local supply (movement cost for the virtual supply trucks = terrain x 3)

However, I could not completely explain what happened. I was observing the village of Brabander (hex 17.13). As long as I controlled the road in 18.12, the local supply in Brabander/rubble was 53 - basically the same as in surrounding hexes, telling me that the rubble had no effect at all. Without control of the road access into Brabander, however, the supply plummeted by -10 to 43%. I would only have expected a drop of 7%:

village (30 for motorized) 
* 4 (motorized in mud) 
* 3 (rubble) 
* 0.02 (2% supply calculation) 
= 7.2

MINES

In the same scenario, I also noticed that clearing an already penetrated minefield increased my local supply (beyond the minefield) by 5%. So it seems as if a penetrated minefield does allow supply to pass through, but still affects it somehow?

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What are your experiences? Is this all working as intended?

[Lethal]

My understanding is that minefields block supply until they are penetrated.

If using the Virtual Supply Truck option I presume rubble would have some effect on the "motorised" supply rate.

[Mowgli]

That was my understanding too, but as I've described in my post, things seem to work a bit differently.

[ComradeP]

It could be that supply trace for hexes with a road "ends" at the hexside, instead of fully taking terrain penalties into account.
That ties in nicely with our findings on supply across streams discussed recently, and across bridges discussed a while ago.

Minefields might inflict a 33,3%, 66,6% or 100% MP penalty depending on minefield strength on VST trucks as well, which could explain a slight decrease.

What I don't understand is what happens with supply as it passes through the RUBBLE hex. In my case the supply from the hex north of Brabander into Brabander decreased supply from 57 to 48. One possible explanation is that RUBBLE movement cost for supply traces is applied on top of increased movement costs for terrain conditions. That is, the terrain cost is applied twice. ((30x4)x0.02)+((30x4)x3x0.02).

However, the unit in the hex south of Brabander had a supply level of only 40, though it's connected to Brabander by a minor road and I would expect supply to be either still 48 or 47 as VST supply movement cost for secondary road in mud conditions modified by strength 1 minefield would be (4x5)x1.33=0.53.

[Outlaw Josey Wales]

Penetrated minefields or rubble tells me they have a cleared path through. But, only one lane. They still have to watch out because there is always one dumbass that will test the limit or just not pay attention to his surroundings. When cleared, a minefield is completely removed. Rubble is the lane is wider, but, the rubble is still there, just pushed further to the side.