When driving along at highway speeds, the majority of the car's
power output is lost to aerodynamic drag. Driving into a
headwind will make the situation worse, requiring more fuel for
a given speed. Conversely, a healthy tailwind will cut the fuel
consumption of every vehicle travelling in that
direction. Strong
side winds can be annoying to car drivers, but in high-sided
vehicles this can be a real danger.
Some highways have barriers, these serve a few functions,
mostly noise attenuation and to mitigate snow accumulation. In
the central reservation between directions, there are also
occasionally sight barriers, as people looking at one accident
frequently cause another.
So, lets have the barriers do some work. Installed in the central
reservation are vertical poles which will act as supports and
pivots. A curved aerodynamic guide vane will be attached to
this such that wind from the side will be redirected through ~90
to generate a slight tailwind on one carriageway. Should the
wind change to the opposite direction, the guide vane will self
pivot so that now it guides the wind to give a gentle tailwind to
the other carriageway. As a side benefit, you will not be able to
see much of the other carriageway and so, head lights will be
less of an annoyance.
Fixed guide vanes on either side will also work, but I like the
pivoting central version for neatness.