This document provides guidance for the installation, inspection, maintenance, and repair of structural supports for highway signs, luminaires and traffic signals. The primary purpose is to provide owners with information that can assist them in managing their inventory, identifying potential problem areas, and ensuring safe and satisfactory performance of these types of ancillary highway structures. The primary reason for compiling this guidance is increasing problems with wind induced vibration, fatigue, and even structural collapse of these support systems. Documented problems with these structures include questionable design and details, poor fabrication practices, and poor installation techniques.