Grants, as authorized by section 22907 of title 49, United States Code, $350,000,000 (increased by $1,000,000) (reduced by $1,000,000), to remain available until expended: Provided , That of the sums appropriated under this heading— (1) $40,000,000 shall be available for projects eligible under section 22907(c)(5) of title 49, United States Code, for projects for commuter authorities, as defined as section 24102(2) of title 49, United States Code, that experienced at least one accident investigated by the National Transportation Safety Board between January 1, 2008, and December 31, 2018