6 U.S. Code § 1139 - Information 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.
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”).
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, and analysis of the extent to which the ISAC is duplicative with the Department’s information-sharing program.
 See References in Text note below.