"Americans drive a staggering number of miles — close to three trillion every year, according to the government. (That is half a light-year, or 120 million trip

"Americans drive a staggering number of miles — close to three trillion every year, according to the government. (That is half a light-year, or 120 million trips around the world.)" It's not often that you see light-years used as a unit associated with driving!