In the City of the Future contest, architects and designers were asked to envision San Francisco in the year 2018. IwamotoScott Artchitects evidently expect quite a lot of change to happen before that time, because their very-futuristic design took first place. The Hydro-Net design features underground traffic tunnels for hydrogen-fueled hover cars which in places link up with the above-ground roads. The city is powered by geothermal and hydro power, and some residents even boast sophisticated cave dwellings.