The "Cool Corridors Act of 2025" reauthorizes and significantly amends the Healthy Streets program, extending its authorization through 2030 . Its primary purpose is to enhance the resilience, accessibility, and safety of the nation's transportation corridors by promoting investments in tree canopy, shade infrastructure, and other nature-based cooling strategies. This initiative specifically targets pedestrian, bicycle, and transit routes to combat extreme heat, improve air quality, and extend the useful life of infrastructure. The Act expands the list of eligible entities to include State and local transit agencies, State departments of transportation, local educational agencies, and various greenspace stewardship organizations. It introduces new definitions for "cool corridor" and "heat mitigation strategies," encompassing a range of activities from tree planting and vegetative infrastructure to cool surfaces and shade structures. Eligible activities are broadened to include planning, design, construction, and maintenance of green infrastructure, deployment of smart sensors, and community engagement for workforce development. The bill prioritizes demonstration projects in geographically and climatically diverse regions, including urban and rural communities with historically low tree canopy or high heat vulnerability. It emphasizes projects that improve access to transit, schools, jobs, or essential services, incorporate long-term maintenance plans, and leverage additional funding. Furthermore, the Act mandates interagency coordination with federal partners like the EPA and USDA, and requires the Secretary of Transportation to provide technical assistance and guidance on project delivery and tree species selection. Grant recipients will be responsible for tree maintenance and must submit annual reports detailing temperature reduction, environmental performance, public health outcomes, and cost-benefit analyses. Within five years, the Secretary of Transportation must report to Congress on the program's outcomes and recommend its permanent authorization and integration into the surface transportation block grant program.