Trucks which pull out and pass each other create enormous drag effects.
Today’s invention tries to minimise these.
Each of the thre trucks driving up the page is equipped with an oval-section trailer. A continuous curtain runs in very low friction rails at the top and bottom edge of the trailer.
Each curtain is driven by a small motor clockwise or anticlockwise, depending on the direction of the curtain to the left (which would be sensed optically, on approach).
In this way, the normal Couette flow between trailers is avoided, since the curtains maintain a flat velocity profile between trucks which overtake each other with small relative velocities.