; 129 Stat. 2835). (b) Requirement Out of funds of the Treasury not otherwise appropriated, there is appropriated to the Secretary of Transportation $250,000,000 for fiscal year 2018, to remain available until expended, to award TIGER discretionary grants for eligible programs and activities in Puerto Rico and the Virgin Islands. 126. Passenger and freight rail improvements (a) Funding Out of funds of the Treasury not otherwise appropriated, there is appropriated to the Secretary of Transportation $600,000,000 for fiscal year 2018, to remain available until expended, for planning and capital costs to build, improve, or expand passenger and freight rail projects in Puerto Rico under titles 23 and 49, United States Code. (b) Eligible uses Of the amounts made available for each fiscal year under subsection (a)— (1) not more than 15 percent may be used for temporary operating assistance for such rail and transit projects as the Secretary of Transportation determines to be eligible