CHDS Thesis Series: The Transportation Security Administration's Four Major Security Programs for Mass Transit - How They Can Be Improved to Address the Needs of Tier II Mass Transit Agencies [video] [open html - 0B]
"The nation's transit agencies in urban areas have been classified as either Tier I or II. Tier I includes the nation's 8 largest urban areas, with all other urban areas classified as Tier II. Since 9/11 a bulk of the federal government's attention and funding has been directed towards Tier I regions. In his thesis, John Joyce argues that, in light of recent foiled plots against Tier II areas, the changing threat environment requires more protection for areas designated as Tier II."
Center for Homeland Defense and Security: http://www.chds.us/