I just came across a statistic of the amount of cars on the road (in the world) is over 600 million, from the article “Global Warming, Focus on the Future”, 1997. There are other statistics about cars on http://hypertextbook.com/facts/2001/MarinaStasenko.shtml, if you would like to take a look feel free. Also at the end of this article is a link to an article entitled “Are ‘Alternative Fuels’ the Answer?” (http://www.nationalledger.com/cgi-bin/artman/exec/view.cgi?archive=3&num=7704). This article shows that in 2003 it was estimated that 204,000,000 vehicles in the US alone.
