Design of automotive emission control along roadways for lead aerosols, sulphur and other pollutants requires a measurement programme which employs rapid and sensitive analytical methods and sampling techniques that permit of tracing of pollutant transport to human receptor sites. Proton-induced X-ray emission analysis was done on roadway aerosols sampled by time-sequence filters. Time variation patterns of elements have given relations which permit of evaluations of area and height-dependent roadway pollutant concentrations and the extent of mixing of local and regional components of aerosol pollutants. The results have been applied to a predictive model for the consequences of a proposed widening of a roadway by the state of Florida.