The Ro-Sa highway develops in a length of approximately 270 km, between Lazio and Campania region, in which are present 26 interchanges to connect this infrastructure with the territory. These two Italian regions are among the most rainy ones. The concept addresses this data redefining unused and unusable areas, in close proximity to the highway, to deliver and accumulate a large amount of water to be purified in special pools and reused for agricultural irrigation. To make it possible we chose the algae growing system, consisting in the cultivation of micro algae that, in addition to purify air and water, produces a large amount of BioFuel and BioGas usable especially for agricultural machines. The waste of the cycle may be used as biomass for energy production. This innovative process could get both public and private funds: the public for testing new methodologies and systems for energy production by renewable sources; the private ones for saving economies in agricultural activity.