The project named Solar Wind is one of the design proposals that was concocted for viaducts in the southern part of Italy. The idea was developed as a way to renovate the existing viaducts [instead of destroying them] which required the addition of necessary “green” features.
So what came up with the designers Francesco Colarossi, Giovanna Saracino and Luisa Saracino was a proposition that needed to fit multiple wind turbines across the entire length and add solar panels on roads. The proposal also included addition of parks, green houses and markets along the road [tourist destination] to make it all the more a profitable venture. Since it does sound promising, you would be glad to know that it did bag the second position in the list of entries.
The project Solar Wind, if put to use, has been estimated to produce about 40 million kilowatt-hour of energy [solar +wind], a sum for powering up 15000 homes.