A method for the precise measurement of moving vehicle emissions is outlined and its role in emissions control programmes considered. The system, which measures carbon monoxide, hydrocarbons, carbon dioxide, nitric oxides and exhaust opacity, can examine over 1000 vehicles per hour at speeds of up to 2000 kph. The results are presented of studies carried out around the world to measure hydrocarbon and carbon monoxide emissions. The effect of mandatory emissions controls are illustrated. The effect of fleet age and maintenance are discussed. Graphs are presented which compare emissions by model year. Maintenance is shown to be of particular importance. Suggestions made for the use of the system, which incorporates license plate reading, include notifying gross polluters and planning emissions control programmes.
Abstract