Unrestricted.2016-11-142011-02-182016-11-142007-08http://hdl.handle.net/2346/9718The wind-induced vibrations of the mast arm of cantilever traffic signal structures can lead to the fatigue failure of these structures. Both full-scale and wind tunnel tests were conducted to study the behavior of the structures. Results of these experiments indicated that when the signals have backplates, vortex shedding can cause large-amplitude vibrations that may lead to fatigue failure. These results contradict what has been generally accepted by other researchers: that galloping is the main cause for the fatigue inducing vibrations and that vortex shedding is of no relevance in this type of structure. A methodology to estimate the fatigue life of these structures was developed. Using the climatology of the region, the methodology was applied as a risk assessment model to traffic signal structures of the city of Lubbock. Guidance is given on how life-cycle cost analysis can be applied to the structures.application/pdfengWind-induced fatigueCantilever trafficRisk assessmentDissertation