A device serves for determining the speed of a passenger-transporting system. The device includes an arrangement of auxiliary elements and a sensing device. The arrangement of the auxiliary elements rotates, in a manner corresponding to a movement of the passenger-transporting system. The sensing device can sense whether an auxiliary element is, or is not, located at a certain sensing location. The auxiliary elements are of a first configuration type and a second configuration type. The sensing device can sense whether an auxiliary element is of the first configuration type or of the second configuration type. Furthermore, the sensing device can assign an auxiliary element of the first configuration type and an auxiliary element of the second configuration type to one another such that the direction of rotation can be determined from the order in which the auxiliary elements are sensed.