Like the pedestrian signs, the Falling Rock signs in Japan show influences from different countries.

The shape of the panel is taken from the Americas. The colour choice and the presence of a borderline also. But take a closer look at the corners: they are only round at the inside. Corners in the U.S.A are rounded at both sides (more examples: Argentina, Chile).

The configuration of the boulders is copied from Pakistan : the same number of boulders, the top rock in a cavity in the wall and the same speed indicators. The shape of the boulders was adapted to make them look more natural.

Though it is difficult to believe that the rock on the ground rests in equilibrium.