With six years of emissions data on more than 2 million metro Atlanta vehicles, researchers have determined the city's fleet is growing old and polluting the air.

The average vehicle in Atlanta has about 90,000 accumulated miles on it, and there are a significant number of vehicles with more than 200,000 miles on them, according to Georgia Tech's Air Quality Laboratory. Researchers analyzed emissions inspection and vehicle registration records to make these estimates.

"Atlantans drive more per day and keep their vehicles longer than drivers in many other major U.S. cities, particularly those in the North where vehicles don't last as long because of salt on the roads," says Dr. Michael Rodgers, director of the Air Quality Laboratory. "Our concern is that we expect this trend to continue, and as vehicles get older, there is degradation. Their emissions control systems become less efficient, and the vehicles release more pollution into the air."

Rodgers and his research team are entering their seventh year of a long-term vehicle emissions monitoring program of Atlanta and short-term studies in other eastern U.S. cities. The Georgia Department of Natural Resources has funded the Atlanta study with about 25 cents of the $25 emissions inspection fee charged per vehicle in the metro area. The U.S. Environmental Protection Agency funds other parts of the program.

The researchers use remote sensing, vehicle registration data, roadway observation studies and laboratory testing to compile emissions data that provides insight into ozone pollution problems.

"Previously, there was not a systematic methodology for determining the effect of aging on a vehicle fleet over time with on-road measurements," Rodgers says. "The Atlanta study is now the oldest monitoring program of its type in the world."

Short-term studies conducted in New York City, Boston, Baltimore, Nashville and Raleigh, N.C., c
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Contact: Jane Sanders
jane.sanders@edi.gatech.edu
404-894-2214
Georgia Institute of Technology Research News
17-May-1999