As said, I haven't seen any cargo trailers with radiused edges (of enough curvature), but with so many miles in so short a time (3k miles x 50 weeks) there will be adverse weather and traffic conditions unavoidably, thus my emphasis. Two of the worst:
1] On a mountain downgrade being overtaken/passed by an 18-wheeler.
2] On a narrow two-laner being passed
in the opposite direction by a pair 18-wheelers close together (which is illegal, by the way; this is well-understood) which causes the 70+ mph bow waves to hit
and reverse direction violently, in less than a second,
multiple times. The complications engendered by the bow wave of the tow vehicle and of the trailer
and that they are being hit by different forces at the same time.
Good aero means more than mpg in situations like the above. These two are perhaps the worst situations where even the best hitch rigging from the best tow vehicle and trailer avail
a little more edge to the driver prior to a loss-of-control accident (as with wind shear in the earlier post.)
An aero trailer with independent suspension and disc brakes with state-of-the-art brake controller is the gold standard.
The latest OEM brake controllers use a combination of vehicle stability control and anti-roll braking forces. What is missing from the OEM brake controller electronics at this point is Anti-Lock trailer brakes.
Thus I would also consider the Antilock module in concert with the offerings of
DirecLink (please request a copy of their free brochure, an excellent overview of braking systems; whether you are experienced or novice) but have no reviews at present of it's performance.
Substantially radiused edges (subject to data) are important as are clean entry/exits for a trailer.
In all of the above, the least input by the driver to maintaining
lane-centeredness in all conditions is also central to higher FE. Steering control.
The trailer that imparts the least force against the steering of the tow vehicle is "safer" (subject to definition), and is easily better for FE.
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