CONSTITUENTS OF HIGHWAY RUNOFF VOLUME III, PREDICTIVE PROCEDURE FOR DETERMINING POLLUTION CHARACTERISTICS IN HIGHWAY RUNOFF

This report documents the development and application of a simple predictive procedure (model) for determining the runoff quantity and quality from highway systems based on the data gathered from 5 monitoring sites around the country. Equations for 3 highway site types were developed to predict runoff volume and pollutant wash-off coefficients for 17 water quality parameters based on total rain, rainfall duration and dry days. Analysis indicated that pollutant accumulation rates within highway systems can be best predicted using average daily traffic values. (FHWA)