Developed by the AASHTO Committee on Bridges and Structures, this Guide is intended to offer guidance on selecting specific, cost-effective preservation and maintenance actions and treatments for agencies wishing to extend service life and estimate needed budgets to optimize performance of bridge inventories. It can be used to help preserve bridges and extend their service life by selecting cost-effective actions and treatments for various bridge elements based on exposure. Specifically, the Guide identifies candidates for bridge preservation; lists actions in bridge preservation; lists costs of actions and time intervals for use of actions; and presents a method of Preservation-Cycle Cost Analysis for cost evaluation of preservation actions, used to compute monetized benefits of preservation.