The primary objective of this research is to enhance the effectiveness of existing stormwater infrastructure (ponds, channels, inlets, etc.) for containing debris (cigarette litter, tire particles, etc.) and microplastics found in highway stormwater runoffs. Through a multidisciplinary approach encompassing hydrology, environmental engineering, and material science, this research aims to identify and implement design modifications that optimize the retention and filtration capabilities of stormwater infrastructures, specifically tailored to address these contaminants. By evaluating factors such as geometry, sedimentation processes, filtration media, and hydraulic efficiency, this research seeks to develop innovative infrastructure designs capable of significantly reducing the transport of debris and microplastics into receiving water bodies. The goal of this research is to provide evidence-based recommendations for enhancing stormwater infrastructure to mitigate the environmental impact of highway-derived contaminants and safeguard aquatic ecosystems.