16 feet tall sounded high to me. I have had to find alternate routes off of an urban loop interstate when my vehicle was only 12.5 feet. So I checked:
According to Wikipedia, 16 feet is the height of the bridges on rural interstates. Urban area interstates are 14 feet or more above the pavement. But there is supposed to be at least one alternate route through an urban area between rural interstates that has 16 feet available. But not all numbered roads meet Interstate standards, especially when an older road is designated part of an interstate.
That still sounds high to me. I remember seeing an army truck that lost its roof against a bridge on I-90 between cities because the soldiers forgot to let the air out of the tires after loading it onto a low-boy trailer.
According to the Federal Highway Administration http://www.ops.fhwa.dot.gov/freight/...view/index.htm
, "No federal vehicle height limit is imposed. State standards range from 13.6 feet to 14.6 feet." That sounds more like what I recall. So you may want to put the sleds behind the bus where they can "draft" the big shoebox, instead of having them on the roof. If you put them on the roof and are lucky, you would only lose the windshields. If you get off the interstate, you may lose the entire sleds.
p.s. I think here in the northeast the diesel pumps have a "winter mix" of #2 thinned out with kerosene. The makers of stationary diesel backup generators warn to only fill the tanks in winter, never allow a tank full of summer fuel to be sitting waiting for a winter power failure. Of course, big stationary generators usually have an AC-powered coolant heater and circulator pump that keeps the anti-freeze above 50°F/10°C.