A rut is a depression or groove worn into a road or path by the travel of wheels or skis or by erosion from flowing water. Ruts can be removed by grading a road surface.

A vehicle with wheels or skis, travelling on a rutted road, if its wheels or skis enter an existing rut will have difficulty steering out of the rut. If it proves impossible to steer out of a rut, though forward and backward progress can be made by the vehicle, it is referred to as being stuck in the rut.

The term stuck in a rut can be used figuratively to refer to a situation in which, as time progresses, the situation is unable to be changed or steered in a desired way.