What is the impact of commercial vehicles on smog? Are there too many of them for individual commuter change to make a difference?
It is true that commercial vehicles/tractor trailers, old school buses and other large vehicles (heavy-duty vehicles), easily identifiable by plumes of black smoke, often times pollute more per vehicle than the average commuter vehicle. However, the sheer volume of commuter vehicles makes commuter vehicles a threat to air quality that is equally as important. Commuter vehicles (light duty vehicles) drive 87 percent of the vehicles miles driven on our roads (heavy-duty vehicles drive just 13 percent), making commuter vehicles the overwhelming cause of our traffic congestion problems. It is easy to underestimate the large amount of air pollution caused by a single automobile. Yet the facts paint a different picture: the average passenger car emits more than 115 lbs. of smog-forming emissions each year (NOx and VOCs). And, the average light truck or SUV emits almost 164 lbs. of smog-forming emissions annually. However, because there are significanlty more passenger vehicles in our most co
