A Canadian motorist managed to film a highway sign bizarrely bending back and forth in violent weather.

The footage shows drivers of vehicles approaching the "bouncing" sign on the Deerfoot Trail section of Highway Two near Calgary slowing down, understandably reluctant to pass under it.

A tanker only just manages to squeeze under the sign, but as the motorist filming the action passes by, a piece of the board breaks off and thunders into the tarmac. That's some pretty strong wind...

Check out the action below.