This handbook is intended to expand upon and provide general information and guidance on the management of systems and associated assets used in the transit operating environment in support of the FTA Transit Asset Management (TAM) rule. It offers a framework that outlines systems theoretical concepts and defines specific classes and types of transit systems to foster consistency in transit system asset management practices. Practical information is presented to assist transit operators in their efforts to inventory systems assets and identify activities and investments needed throughout the system life cycle to receive the most value from the system.