The advantages of limiting car usage would be better because passenger cars are responsible for 12 percent of greenhouse gas emissions in europe. And up to 50 percent in some car-intensive areas in the united states. Diesel fuel was blamed since france has a tax poilcy that favors diesel over gasoline. Diesels make up 67 percent of vehicles in france, compared to a 53.3 percent average of diesel engines in the rest of western europe, according to reuters.

The day without cars is part of an improvement campaign that began in bogota in the mid-1990s. It has seen the consruction of 118 miles american city, according to mockus, the city's mayor. Parks and sports centers also have bloomed throughout the city; uneven, pitted sidewalks have been replaced by broad, smooth sidewalks; rush-hour restrictions have dramaticly cut traffic; and new resturants and upscale shopping districts have cropped up.

I think that this a great idea to do and demographic shifts in the driving population suggest that the trend may accelerate. There has been a large drop in the percentage of 16- to -39 year olds getting a licenses as they age, mr. sivak's research has found. A study last year found that driving by young people decreased 23 percent between 2001 and 2009.