In-Service Evaluation of Temporary Sign Support Systems Against Wind Load

This short study analyzes the performance of multiple temporary sign support systems under windy conditions and provides recommendations to the Bureau of Safety Programs and Engineering of the Illinois Department of Transportation (IDOT). The efforts included a literature review that summarizes past studies on the use of temporary sign support systems and the effects of winds on their structural integrity and stability as well as current practices on the use of such systems. Then, a set of field experiments were performed to test a list of temporary sign support systems under different natural and truck-generated wind loads, revealing critical conditions where they can fail. Finally, we extended a finite-element analysis to evaluate the structural impact of natural and truck-generated winds on selected sign support systems. Slow-ramping or longer-duration gusts produce greater sign deflections than short-duration gusts, and winds induced by a single truck or a three-truck platoon generate no significant sign deflection. These findings are summarized into deployment recommendations that account for the types of sign support systems and wind gust speeds. These recommendations will help IDOT make deployment decisions based on historical maximum gust speed data in each IDOT district per season.