Producing DynaSignal: A Novel Aerodynamic Solution for Traffic Signal Lights

Cantilevered traffic signal structures are critical components of urban infrastructure. However, their slender, cantilevered design makes them particularly vulnerable to wind-induced vibrations, which can lead to fatigue failures at the pole-to-mast arm connections—locations where stress concentrations are highest. Despite ongoing research into fatigue-rated joints and passive damping devices, limited attention has been given to the real-world aerodynamic behavior of these structures under natural wind conditions.

The Final Report for NCHRP IDEA Project 241: Producing DynaSignal: A Novel Aerodynamic Solution for Traffic Signal Lights builds upon a prior IDEA Type I project that explored aerodynamic mitigation strategies for traffic signal structures through wind-tunnel testing and hybrid numerical simulations. The current IDEA Type II project advances this work by implementing and validating the mitigation strategy on a full-scale traffic signal structure exposed to natural wind conditions. While the concept of using flat-plate modifications to enhance aerodynamic damping is not new, the novelty of this project lies in its scale and scope of validation—specifically, the long-term field monitoring of an in-service structure and the quantified demonstration of fatigue-life extension.