A control system that steers a tractor vehicle with a trailer has at least one electronic control unit which has interfaces to a first sensor device for sensing the current bend angle, a second sensor device for sensing the required driving space of the tractor-trailer combination, and a third sensor device for sensing the driving space which is present. The control unit also has a collision prediction unit for comparing the required driving space with the driving space which is present while taking into account the current bend angle, and a collision prevention unit which determines, through interaction with the collision prediction unit, a bend angle which is the maximum permissible one for preventing a collision. The collision prevention unit indicates a setting of a bend angle which exceeds the maximum permissible bend angle as critical in terms of a collision and prevents the setting or permits it only after a predefined delay.