title: Emissions reductions as a result of automobile improvement.
abstract: Remote sensing of light duty vehicle on-road tailpipe exhaust has been used to measure on-road mass emissions of automobile fleets in Denver for 13 years and in two other U.S. cities for 5 years. Analysis of these fleets shows that newer automobiles, during a period of fairly constant new car standards, have become continually less polluting independent of measurement location. Improving emissions control technology spurred by federal regulations is thought to have brought about these trends.
authors.affiliation: Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA.
authors.forename: Sajal S
authors.initials: SS
authors.lastname: Pokharel
authors.forename: Gary A
authors.initials: GA
authors.lastname: Bishop
authors.forename: Donald H
authors.initials: DH
authors.lastname: Stedman
authors.forename: Robert
authors.initials: R
authors.lastname: Slott
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001336:Automobiles / Q000592:standards*; D002248:Carbon Monoxide / Q000032:analysis; D002947:Cities; D006838:Hydrocarbons / Q000032:analysis; D009569:Nitric Oxide / Q000032:analysis; D014481:United States; D001335:Vehicle Emissions / Q000032:analysis / Q000517:prevention & control*
chemical_list: D000393:Air Pollutants; D006838:Hydrocarbons; D001335:Vehicle Emissions; D009569:Nitric Oxide; D002248:Carbon Monoxide