Road networks and vehicular traffic are indispensable to modern societies, yet they are pervasive sources of chemical pollution with profound ecological consequences. Pollutants are emitted through multiple pathways, most prominently exhaust emissions, road runoff, and the resuspension of fine particles, and they disperse across air, soils, and aquatic systems. Once in the environment, they degrade air quality, contaminate waters, alter soil chemistry, impair vegetation, and bioaccumulate in wildlife, ultimately disrupting communities and food webs. At the global scale, greenhouse gases from traffic contribute substantially to climate change, linking local emissions to planetary disruption. While emission controls are reducing exhaust-related impacts, non-exhaust sources including tire abrasion, brake wear, and road surface degradation are now becoming dominant contributors. These processes release microplastics, heavy metals, and organic pollutants, underscoring the enduring and evolving nature of road-derived contamination. Beyond ecological damage, road pollution also raises concerns of environmental justice, as disadvantaged communities near major transport corridors face disproportionate exposure. Mitigation requires integrated strategies that combine cleaner vehicle technologies, improved infrastructure, and green systems capable of intercepting pollutants before they reach sensitive habitats. Yet technological progress alone is insufficient: durable solutions depend on policy frameworks that balance efficiency, equity, and long-term sustainability. Addressing chemical pollution from roads therefore demands innovation in both science and governance, together with the alignment of mobility systems with broader climate and biodiversity goals.