A current state-of-the-art survey is presented with regard to painting of highway structural steel. A thorough literature review was conducted and an inspection and evaluation made of more than 4,000 paint exposure tests. Paint film thickness measurement studies were made. Specific recommendations are given for selecting typical paint systems on the basis of six environmental zones, which represent the range of severity of environment in which highway steel structures are located in the United States. Model specifications are suggested for surface preparation, application, material procurement, and paint system.