The report is designed to provide transportation tunnel owners and operators with guidelines for protecting their tunnels by minimizing the damage potential from extreme events such that, if damaged, they may be returned to full functionality in relatively short periods. The report examines safety and security guidelines for owners and operators of transportation tunnels to use in identifying principal vulnerabilities of tunnels to various hazards and threats. The report also explores potential physical countermeasures; potential operational countermeasures; and deployable, integrated systems for emergency-related command, control, communications, and information.  View Report