This dovetails nicely with a new study from Canada, which found 25% cars produce 90% pollution. https://www.sciencedaily.com/releases/2015/04/150421105344.htm

This dovetails nicely with a new study from Canada, which found 25% cars produce 90% pollution. https://www.sciencedaily.com/releases/2015/04/150421105344.htm https://www.sciencedaily.com/releases/2015/04/150421105344.h... "The study made on-the-spot measurements of 100,000 vehicles as they drove past air-sampling probes of the main laboratory on College Street, one of Toronto's many major roadways." Also interesting was their findings of how pollution from roads permeates the surround areas, and the complex ways pollution from multiple roads produces additive exposure.