Oddly enough, I bike commute almost daily but consider these car-free days to be more dangerous! Inexperienced cyclists, especially children, scare me more than cars.

I wonder if any city in America could do a day without cars. 

This is the best line: "Unfortunately, environmentalism is one of the greatest marketing flops in the history of homo sapiens"

That IS a great line. Environmentalists have done themselves a disservice by being bad at marketing.