Development and validation of a test method to assess the wind-induced response of span wire traffic signal systems

ABSTRACT To better understand the wind-induced response of span-wire traffic signal systems a full-scale experimental study was carried out using two testing apparatuses: a short-span test frame with coil springs installed at either side of the wires and a long-span test frame. An analytical model was developed to select the appropriate coil spring stiffness that will allow the short-span frame to match the static and dynamic behaviour of the long-span frame. Results showed good agreement between the two test frames for the total drag, total lift and inclinations experienced by the traffic signals. The two test frames also agreed well in identifying the critical wind speed for the onset of aerodynamic instability, which for some signal and hanger configurations was as low as 30 m/s.