There are a lot of trucks on the road. In the U.S. alone, there are an estimated 2 million tractor trailers in active service. The vehicles serve as the core transportation method for goods in much of the world, thanks to their ability to go where planes, trains, and boats cannot. They are also big contributors of greenhouse gases and other air pollution. This is partly because they’re so heavy, but it is also because they spend so much time on the road. A typical family car will spend most of its time in a garage or parking lot, where a tractor trailer will be driving for as many hours as is legally allowed.
Mercedes-Benz is looking to address some of the pollution problem with a concept for a new aerodynamic semi-trailer called the Aero. The trailer is intended to be a companion to the newest version of their Actros truck. Both components boast an improvement in wind resistance. The Aero trailer gets an 18% reduction over conventional box trailers (with a corresponding 5% reduction in fuel consumption in regular traffic). There’s just one problem: The proposed trailer isn’t street legal.
The issue is that part of the design of the trailer includes a tapered extension to the tail end that runs a foot and a half past the maximum allowable trailer length in Europe. Mercedes-Benz says that this taper accounts for a third of the improvement in efficiency and they are confident that a change to the laws are possible. Why not just make the trailer 18 inches shorter? Mercedes-Benz’s press release holds a clue.
“The fundamental feature of the revolutionary Aero trailer is to be found in the trailer’s load compartment, whose dimensions remain totally unaffected,” it says, “The familiar box – measuring 13.6 m in length, 2.55 m in width and with an overall height of four metres – remains available for the freight, just as before.”
The tractor trailer is merely one component in a much larger and highly standardized logistics network–in other words, being green is as much a matter of the system’s design as it is about the design of the actual pieces.