6 U.S.C. § 1139

(a) Intelligence sharing The Secretary shall ensure that the Department of Transportation receives appropriate and timely notification of all credible terrorist threats against public transportation assets in the United States. (b) Information Sharing and Analysis Center (1) Authorization The Secretary shall provide for the reasonable costs of the Information Sharing and Analysis Center for Public Transportation (referred to in this subsection as the “ISAC”). (2) Participation The Secretary— (A) shall require public transportation agencies that the Secretary determines to be at high risk of terrorist attack to participate in the ISAC; (B) shall encourage all other public transportation agencies to participate in the ISAC; (C) shall encourage the participation of nonprofit employee labor organizations representing public transportation employees, as appropriate; and (D) shall not charge a fee for participating in the ISAC. (c) Report The Comptroller General shall report, not less than 3 years after August 3, 2007 , to the appropriate congressional committees, as to the value and efficacy of the ISAC along with any other public transportation information-sharing programs ongoing at the Department. The report shall include an analysis of the user satisfaction of public transportation agencies on the state of information-sharing and the value that each system provides the user, the costs and benefits of all centers and programs, the coordination among centers and programs, how each center or program contributes to implementing the information sharing plan under section 1203, 1 1 See References in Text note below. and analysis of the extent to which the ISAC is duplicative with the Department’s information-sharing program. (d) Authorization (1) In general There are authorized to be appropriated to the Secretary to carry out this section— (A) $600,000 for fiscal year 2008; (B) $600,000 for fiscal year 2009; (C) $600,000 for fiscal year 2010; and (D) such sums as may be necessary for 2011, provided the report required in subsection (c) of this section has been submitted to Congress. (2) Availability of funds Such sums shall remain available until expended.