Many Minnesota bridges have older barriers or parapets that met the design code at the time of original construction but no longer meet current standards. Document the use of post & beam, type G, type J, and type F barriers on MnDOT bridges. How many years was each used? How many bridges have each type? What is the capacity of each barrier type? Develop guidance and criteria for determining when an existing barrier should be upgraded or replaced with a barrier that meets current standards. Will require reviewing many bridge plans, must understand AASHTO bode barrier design provisions (past and present).