This report, prepared by the Blue Ribbon Panel on Bridge and Tunnel Security, presents a set of recommendations to achieve the overall goal of reducing the vulnerability of the Nation's bridges and tunnels to terrorist attacks. The recommendations are divided into three areas: institutional, fiscal, and technical. The institutional recommendations include: improving interagency coordination; developing outreach and communication strategies for use with decisionmakers, facility owners/operators, designers, and elected officials; and clarifying the legal responsibility of State and local transportation officials with respect to their responsibility to act on the indications of risk studies for their facilities. The fiscal recommendations include: developing new funding sources for bridge and tunnel security, and addressing the need for flexibility to fund critical structures on a programmatic basis. The technical recommendations include: the Federal Highway Administration should work with the Transportation Security Agency to prioritize the Nation's critical bridges and tunnels and to administer fund allocation to responsible agencies to meet high priority security needs; and developing and validating new engineering standards that address the growing security concerns regarding the Nation's bridges and tunnels. Tables, references, and appendixes