A module for determination of speed set-point values vref for a vehicle's control systems, comprising an input unit adapted to input, e.g., by the vehicle's driver, of a reference speed vset which is the speed desired by the driver for the vehicle. The module includes a horizon unit to determine a horizon by means of received position data and map data of an itinerary made up of route segments with at least one characteristic for each segment; a processor unit to calculate vref for the vehicle's control systems across the horizon according to rules pertaining to categories in which segments within the horizon are placed, so that vref is within a range bounded by vmin and vmax, where vmin≦vset≦Vmax, which control system regulates the vehicle according to these set-point values.