Ellie H. Fini at North Carolina A & T State University has developed a product that can be used as a binder when laying asphalt paving. Better Roads has an article on it here:
PiGrid. The product is made from pig manure. Yep, that wonderful stuff that pig farmers would love to get rid of. Now they may be able to sell it to the road construction industry. The story in the link just mentions it as a binder for asphalt production. A story in Wired Magazine this month (July 2013) says that it can be used by itself. Apparently several states are testing it for use on their roads. One big advantage? It is a lot cheaper than asphalt. It is also much more energy efficient, which is why I put it in Climate Change instead of General Science.
So in the future you may be able to thank all those wonderful pig farmers for your nice smooth ride.
Bill Gill