The BCQ Sarajevo Bridge is a conceptual design -- soon to become a reality -- that cleans itself. It does this thanks to the use of photocatalytic concrete, which essentially breaks down smog and other dirty particles that land on the concrete. When it rains, all of the dirt and grime is washed away. The bridge was designed for the city of Barcelona, which wanted it to become more pedestrian-friendly.
To that end, BCQ is installing glow stones, which gather sunlight during the day and disperse it during the night to provide light. There will also be plants installed along the walkways to beautify things and photovoltaic panels to power some LED lights. The BCQ Sarajevo Bridge is an example of how eco-friendly design can be practical and functional, not to mention realistic in terms of expectations and returns.