This is an unexpected phenomenon!
Look at these lamp posts swaying during a violent wind storm near Lofthouse, England.
The violent swaying of lamp posts in this videois an example of “vortex-shedding.” It has been recorded near Lofthouse, England by someone driving on M62.
But why are the posts swaying while other tall objects in the background, including other lamp posts aren’t moving at all.
Vortex-shedding occurs when the natural frequency of a lamp column matches the speed of the wind. It only happens at certain wind speeds and is a fairly rare event.