DOWNTOWN / TAMPA, FL – NOV 12, 2015: The newer, more secured horizontal traffic signal lights are the optimal choice for cities that tend to have high winds such New Orleans and Tampa.
Horizontal lights are usually anchored multiple times along the entire length of the light by welds or bolts. Comparably, vertical traffic lights are usually anchored on a horizontal beam in just one area but are still secure.
However, the traffic lights that only hang from a tether, usually by a steel cable of some kind, are the ones that swing violently in high winds but rarely actually fall, such as the new traffic lights recently constructed in Sun City Center, FL.
Downtown Tampa still has vertical traffic lights, both tethered and secured, at different intersections. You can see a tethered traffic light on Cass Street Bridge.