Abstract: A signalling device for warning motorists of danger including, in combination: a planar sign having a first surface with indica thereon; a housing having a top wall with a slot formed therein and a flange secured to the sign; a motor positioned within the housing, the motor having a horizontal output shaft, a disk coupled to the output shaft, the disk adapted for rotational movement, and a hole formed within the periphery of the disk; a generally vertically extending flag pole having an upper extent and a lower extent, the lower extent being pivotally connected to the bottom wall of the housing, the flag pole adapted for cyclic pivotal movement, a horizontal hole formed adjacent to the lower extent of the flag pole, the flag pole being positioned such that it extends through the slot of the housing, the upper extent of the flag pole extending above the housing and the top portion of the sign; an s-shaped pin having a first end and a second end, the first end positioned within the hole formed adjacent to the l