Correlation between vehicle miles driven and air quality in the U.S

In recent years, the United States has experienced an increase in gas prices and consequently a decrease in vehicle miles driven. From January through September 2008, Americans drove 79 billion fewer miles as compared to the same period in 2007. This study focuses on the hypothesis that a reduction in vehicle miles of this magnitude should be correlated with a signature in surface air quality. Ozone and PM2.5 levels are examined in both years to determine if there is a direct correlation between the amount of miles traveled and of those pollutants. Meteorological fields are incorporated to attempt to normalize the differences in pollutant concentration due to weather influences. Preliminary results suggest that the signature of a decline in Ozone and PM2.5 is apparent in the data. Results point to greater, self-imposed, conservation during times of high gas prices lead to cleaner air. This poster will report on the methods of data reduction and analysis, with an emphasis on understanding whether the differences are indeed the result of fewer emissions or a consequence of differences in weather patterns between the two years.