TRB’s Transit Cooperative Research Program (TCRP) Synthesis 80: Transit Security Update explores transit-related counterterrorism and anti-crime security measures and practices; examines crime and security incident trends; and highlights other related topics, including major issues and obstacles to security and policing management.  The report is an update to TCRP Synthesis of Transit Practice 21: Improving Transit Security, which did not address terrorism.  A link to the report can be located at https://www.trb.org/news/blurb_detail.asp?id=10105.