Bunkers Trenches Improved Positions

[Dog Soldier]

The problem with fortifications being downgraded when a unit in travel mode moves through the hex is for both roads and rail movement.  While not explicitly listed, I believe the intent is for any movement using a "pathway" in column (aka Travel mode) through an unoccupied hex to not cause the IP, TRENCH, BUNKER, PILLBOX or FORT to be downgraded.  The traveling unit stays on the "pathway" and doesn't interfere with the fortification.

Leaving a fortification in the field or traveling through one without a pathway should degrade the defensive capability since the moving unit would have to cut a path through the hex.

Also this discussion should consider the zeroing in or sighting of weapons in the fortified position.  That was mentioned somewhere before as part of the rational for the defensive percentage for all fortifications.  Hard fortifications, have the additional percentage added to direct fire attacks they make on the enemy when occupying such positions to show the increased value of the weapons registering from that position.  The unit leaving the position cannot leave that for the next occupant unless the new unit enters and stays in the fortification before the original unit leaves.
Does this help explain the answer to downgrading?

Dog Soldier

[typhoon]

It all helps to understand things and it’s always good to see a lively conversation. My contention was based on preparing good defensive positions in advance. With the downgrading this becomes much harder. 
  If positions did not downgrade unless there was a change of ownership it would make me cling to those frontline positions much less stubbornly and make the longer campaigns much more playable long term. For now engineers and corp troops that would be building those defences are thrown into the frontline. The engineers hoping by digging to turn the trenches into bunkers with low % chances. The Corp troops moving up to gain time forcing the enemy one more disruption before the assaults come in.
  This may be a reflection on my own play style but I would like both options to be viable strategies in game.

[Outlaw Josey Wales]

Also, the times I was in, we had the practice of filling in our foxholes when we left our position for a new one. If the enemy wants it, he'll have to dig his own hole. How much that was done in WW2, I don't know.