1. A method performed by a data processor for automatically determining set-point values for a vehicle's control system, the method comprising the steps of: A) determining a horizon by means of position data and map data of an itinerary including route segments with at least one characteristic for each segment; B) calculating threshold values for said at least one characteristic of each segment according to one or more vehicle-specific values; C) comparing said at least one characteristic of each segment with the calculated threshold values and assigning each segment within the horizon to a respective category of a plurality of categories according to the results of the comparisons, wherein the threshold values serve as boundaries for the assigning of the segments to the plurality of categories; D) calculating set-point values for the vehicle's control system across the horizon according to rules pertaining to the categories to which segments within the horizon are assigned; E) regulating the vehicle according to the set-point values.