time for more moving math !
semi trailer max legal weight = 80,000 lbs GVWR
out of that tractor = 25,000, flatbed trailer = 10,000, payload = 45,000
you can fit 4 X 12" PODS containers on a single flatbed trailer, each one weighing 1750 lbs, for a total of 7,000 lbs of container weight. by contrast an enclosed "dry box" trailer is only about 3,000 lbs heavier than a flatbed trailer, so four PODS containers on flatbed versus an enclosed dry box trailer will add 7,000 - 3,000 = 4,000 of dead weight - this out of 80,000 GVWR or 5% of total possible tractor trailer weight, and about 1,000 lbs PER 12 FT CONTAINER.
now why am i doing this comparison - because ABF Freight U-Pack is using enclosed trailers and i wanted to estimate how much weight that saves by not having separate containers. it seems you save about 1,000 lbs per 12 foot PODS container. and indeed when you compare U-Packs own relocube container to their own Trailer service - the Trailer comes out cheaper by about that much.
so Trailer wins, right ? not so fast ...
when movers get tired they break things. i foolishly let my mother pack her things herself and she grossly overloaded the boxes to where the movers could barely lift them. she simply put a large box on the floor and kept adding items to it with no regard for the weight. when movers were struggling moving those boxes through the laundry room which is entryway from the garage - they broke the Samsung dryer in the new home by crushing it with one of these heavy items.
what does that have to do with semi trailers ? the point is that a container ( unlike a Penske truck or ABF trailer ) is at GROUND LEVEL, which means less work for movers. also i was able to get Penske into the driveway but some Nigger driving for ABF freight probably wouldn't be able to do it and just park the trailer on the street making movers carry everything extra 40 feet or so. the sooner the movers get tired the sooner they will start breaking things.
in other words with containers you pay more because ultimately you are paying to move an extra 1,000 lbs of weight from the container itself - but the benefit is the items are placed closer to the entrance of the home and at a lower level ( no need for ramp ). this means movers have to do less work, stay fresher and are less likely to break things.