A discretionary grant program designed to accelerate the deployment of advanced bus technologies. The program offers an opportunity to incorporate low-emission vehicles into the mainstream of the nation's transit fleets and supports FTA's efforts to advance emerging clean-fuel technologies. Additionally, this program was developed to assist transit systems in purchasing or leasing low emissions buses and related equipment, constructing alternative fuel fueling facilities, modifying existing garage facilities to accommodate clean fuel vehicles and assisting in the utilization of bio-diesel fuel. Eligible recipients are those entities eligible to receive formula funds located in urbanized areas with a population greater than 200,000 or a state with an urbanized area below 200,000 in population which is designated as a clean air non-attainment or maintenance area for ozone or carbon monoxide. Funds are allocated according to a legislative formula based on the number of vehicles in the bus fleet and the number of bus passenger miles as weighted by severity of non-attainment for either ozone or carbon monoxide.