Primary sources of pollutant export from roadway surfaces originate from traffic activities, fluid leakage and spill, vehicular component wear, roadway maintenance, pavement degradation, and wet and dry atmospheric deposition [4–7]. Pollutant loadings observed in highway runoff, expressed as pollutant mass export per unit contributing drainage area per event, are generally related to traffic volumes, precipitation characteristics, highway surface types, and highway construction and maintenance activ- ities [8]. Various aspects of water quality degradation due to roadway inputs have been documented [9–14].