Movement point confusion

[Liebchen]

I thought I knew how to move units, but this one's got me scratching my head. The ground condition is soft, and a motorized unit in T mode who has 26 remaining movement points cannot seem to move a single hex along a secondary road, up a 20 meter grade.

By my calculation, this should cost 10 MPs, calculated as:

5 (secondary) x 1.5 (soft) = 8
+ 2 for the grade = 10

So why can't this unit, who has 26 MPs left, move to that hex? What am I missing? Here are snapshots of all of the relevant data. Note the grayed out village hex:
  Movement question.jpg (Size: 187.25 KB / Downloads: 135)

Never mind, I figured it out. It's the stream, which costs 20 MPs. (Doy!)

[Dog Soldier]

Streams will do it alright!

Dog Soldier

[Volcano Man]

Yeah, it is hard to tell from the tiny image but it looks like a stream is there with no bridge. If so, that is +20, then the change in elevation is +10 or more.

[Liebchen]

Pretty sure that the elevation change only costs +2, since it was only a 20 meter elevation and the pdt said +10/100 meters. Isn't this prorated?

...and what about the fact that there's a secondary road there? Shouldn't the T mode negate the stream in favor of this road?

[Dog Soldier]

No, if there is no bridge, then think steep banks and a ford is all you have on a secondary road. Even if the banks were shallow, the stream bed could be mushy.

Either way it would be slow going to get a full unit across the hex side.

Dog Soldier