Cradle hole

a sunken place in a road, caused by thawing, or by travel over a soft spot.

See also: Cradle

References in classic literature ?
went the first sleigh over a cradle hole in the snow of the road, and each of the other sleighs jolted in the same way, and rudely breaking the frost-bound stillness, the troykas began to speed along the road, one after the other.