Highways gather pollutants from vehicles during dry periods, which are washed off into water bodies during storms. This study looked at the types and amounts of pollutants in stormwater runoff from highways. They found that pollutants like metals, oil & grease, and toxic chemicals were present in high concentrations during the initial 30 minutes of a storm. The pollutant concentrations ranged from 154.7-257.1 mg/L for suspended solids, 755,138.9-197.6 mg/L for COD, 3.5-6.4 mg/L for oil & grease, 6.3-9.2 mg/L for TN, and 2.3-3.31 mg/L for TP. The first flush effect, where the highest pollutant concentrations occur early in a storm, was observed in most storm events.