of such title, and the demonstration and deployment of innovative mobility solutions as authorized under section 5312 of such title, $510,000,000, to remain available until expended: Provided , That of the amounts made available under this heading— (1) $374,000,000 (reduced by $1,500,000) shall be available for the buses and bus facilities competitive grants as authorized under section 5339(b) of title 49, United States Code: Provided , That activities that increase green space surrounding a bus transportation hub structure are eligible for a grant under this paragraph: Provided further , That the minimum grant award shall be not less than $1,000,000