Vehicle-trailer backing system with jacknife protection

A method of maneuvering a vehicle-trailer assembly in reverse travel with a backing system includes: initiating a backing mode for the backing system; determining a current relative position representing a relative angle between the vehicle and the trailer; retrieving an operator proficiency setting selected by an operator; determining a maximum allowable relevant position for the current trailer based on the selected operator proficiency setting and the current trailer calibration data; receiving a position adjustment request via an input device; determining a new relative position request based upon the position adjustment request and the selected operator proficiency setting; comparing the new relative position request to the maximum allowed relative position setting to determine if the new relative position is below the maximum allowed relative position setting; setting a new relative position to the new relative position request when the new relative position request is within the maximum allowed relative position setting.