I also think that there is an abrupt elevation change.
No road hexside is being crossed, btw.
See B19.4 example : even though movement is between two -1 level Locations, the intermediate level MF must be spent - and the EX speaks of A10.51 Abrupt Elevation change rule). It is about Gullies, but the phenomenon is identical when moving from IN a sunken road to a non road hexside connected adjacent hex.
I do see the reasoning both you and Klas are using. And you definitely have me waffling in my opinion... I'll still repeat that none of the examples you gave (B19.4) nor any of the examples given under the Abrupt Elevation Change rule (10.5) show a case where
both Locations
and the entire hexside all exist at the same level.
In addition, the Sunken Road rules do leave some ambiguity:
B4.4 Movement costs across a Sunken Road hexside are identical to those for other roads. Only the entrance costs of a Sunken Road hex through a non-road hexside differ.
B4.41 Infantry/Cavalry
entering a Sunken Road hex through a non-road hexside do so at a cost of two MF.
There is no cost for leaving a Sunken Road hex other than the normal penalties (10.4) for moving to higher elevation.
As I stated above, 4.4 refers only to entering the sunken road hex and the second sentence of 4.41 only discusses cases when exiting to a higher elevation (wherein lies the ambiguity).
But in the end, I would probably feel different if the hill's crest in W7 was drawn to bulge outwards, more-completely running along the V6/W7 hexside. And with that image in mind, I am now doubting my previous post. I can't help suspecting that the board's designer had my interpretation in mind for this particular hexside, but perhaps Perry should be asked just to have an official verdict on record...