A report from Ward's claims there are over one billion cars on the road worldwide. Not surprisingly, most of the automobiles are found in the US.
The United States has 240 million cars or roughly 1 car for every 1.3 people. This number dwarfs any other country, but it has stayed the same over the past few years. Almost everyone who wants a car has one and we are merely replacing our stock.
China, though, is exploding. The Asian country is in second place with 78 million cars (about 1 for every 17.2 people), but it's adding 20 million new cars each year. This number is expected to climb to 40 million in the next few years.