The amount of traffic on a given stretch of highway may greatly influence the surface accumulation of pollutants and the removal of solids and other pollutants from highway lanes and shoulders [15]. It is typically reported as average daily traffic (ADT) counts. Although ADT reflects the variation of land use in areas surrounding a highway corridor, its significance appears to be more pronounced on a broad scale and variations between different roadway segments could be attributable to other factors [10,16]. The number of vehicles traveling during storm was observed to be important when predicting pollutant loadings of lead, zinc, chemical oxygen demand, and total Kjeldahl nitrogen [15].