Abstract: Device for determining a desired contour of a ground surface, for instance a road surface, relative to the actual contour of that ground surface, at least comprising measuring unit for generating along a determined distance from a ground surface actual values for the height and position of a number of points of that ground surface relative to a determined reference point, wherein the measuring unit comprise a laser light source which can be placed at a measuring point above the ground surface and which is adapted to generate a laser beam moving over the determined distance from the ground surface, sensor for detecting the laser beam reflected by the ground surface to the measuring point, time-measuring unit for determining the transit time of said laser beam between the laser light source and the sensor, and processing system for generating from signals from the laser light source, the sensor and the time-measuring unit of actual values for the height and the position of a number of points of this ground