SIGN STRUCTURES UNDER WATCH

Recent failures of traffic sign structures have caused states to strengthen their inspection procedures and develop sign structure management programs. Many agencies have had to examine the question of responsibility for sign evaluation, inspection, and maintenance and in most cases, this task falls to the agency's bridge and structure section. A sign-structure management program should include an inventory, inspection report, and maintenance program. Each of these program components is addressed along with a description of the three main types of sign structures: simple span structures, cantilever structures, and bridge-supported structures. The article explains that the inspection of sign structures involves traffic control, access, inspection techniques, and reporting. On high-traffic, high-speed highways, the traffic control effort can be as challenging as the actual structure inspection. Often inspectors must wait to close lanes to reach the structure in need of inspection. It is emphasized that sign structures should be inspected by trained professionals who have an understanding of the load path through the structure and the particular types of defects which have been found or could be expected on these structures. The article describes visual examination of structures, reporting systems for the inspection, and conversion of the data from the inspection into the basis for a maintenance program.