 Heavy-duty vehicles account for less than 5% of the vehicles on Connecticut's roads, but they are responsible for more than half of the state's air pollution. New Haven Mayor Justin Eliker says the new truck will take the equivalent of 14 passenger vehicles off the road. Diesel-fueled power trucks pollute at very, very high levels, and in particular, they have particulate matter, nitrogen oxide, that significantly contribute to asthma and other health-related issues and air quality issues.