L. David Roper
http://www.roperld.com/personal/roperldavid.htm
6 April, 2016
National highways and railroads utilize large areas of land. If those lands were covered by solar-PV panels a huge amount of electricity could be produced from incident solar energy. Such coverings would also shield the roadways from snow and rain. The collected energy could be used to inductively charge electric vehicles as they travel under the cover; extra electricity could be fed into the national grid during peak-use hours.
Lighting of highways at interchanges could be powered by solar-PV arrays on the land between the roads; the daytime collection of the solar energy could be fed into the electric grid during peak-use hours and then taken out of the grid at night during low-use hours.
Another concept that is being considered is that the highway itself is made of solar panels.