EVALUATION OF THE CALINE4 LINE SOURCE DISPERSION MODEL FOR COMPLEX TERRAIN APPLICATION

CALINE4, the latest version of the California Line Source Dispersion Model, is evaluated for use in complex terrain. Data from air-quality studies connected with a transportation improvement project along State Route 203 at Mammoth Lakes, California, are used for this purpose. A comprehensive tracer gas release experiment performed after completion of the project is described. Based on comparisons with the CALINE3 model and previous results for CALINE4 in flat terrain, model performance for receptors near the roadway in complex terrain is judged adequate for impact assessment purposes. Predictions for more distant receptors are much less reliable.