The United States Department of Transportation announced the results of a study assessing the vulnerability of the national transportation infrastructure that relies on GPS. The study notes that GPS is susceptible to unintentional disruption from atmospheric effects, signal blockage from buildings, and interference from communications equipment in addition to potential deliberate disruption. It contains several recommendations to address the possibility of disruption and ensure the safety of the national transportation infrastructure. U.S. Transportation Secretary Norman Y. Mineta has asked administrators of each DOT operating administration to review the report and consider backup systems for each area of operation in which GPS is used for critical transportation applications. Findings are due back to Mineta in 60 days. To view the report, visit www.navcen.uscg.gov.