The AASHTO Guide to Preservation of Highway Bridge Decks, First Edition (2023), describes preservation treatments that extend the service life of highway bridge decks. Sections cover preservation treatments for bridge decks, including deck overlays, surface sealers, and deck repairs, followed by methods for evaluating the condition of bridge decks. A separate section addresses the selection of preservation treatments, considering the factors in deck capacity and durability that influence whether a deck is a preservation candidate. The guide also treats the costs and benefits of deck preservation so agencies can weigh treatment investments against expected life extension. The guidance is designed for decks in fair or good condition with significant remaining service life. It is intended for bridge owners, maintenance engineers, and asset management staff planning deck preservation programs.