attaching elements 2 on a surface the fastening device 1 comprises an oscillating unit 10 with a rotating sonotrode 6 the sonotrode 6 is designed as a sonotrode roller which is preferably excited by a converter 7 to oscillate in a radial direction the oscillation is transmitted to the element 2 and has the effect that this element is plastified locally rollers 4 5 are arranged in front of and behind the sonotrode roller 6 in the working direction x direction these rollers serve for pressing the element 2 onto and into the surface of the background if applicable rollers 4 5 are also guiding and support rollers a cutting and detaching device 11 12 are arranged in front of and behind the rollers these devices comprise a blade each and when activated cut off the element 2 or detach it from the surface on which it is fastened fig4 shows a schematic section along the axis of the sonotrode roller 6 according to fig3 as may be recognised the sonotrode roller 6 consists of a plurality of stacked disks 18 being connected to one another centrically via thin locations 13 the oscillation of the converter 7 is preferably introduced perpendicularly to the axis a of the sonotrode roller the invention may be summarized as follows an environmentally friendly and safe method for attaching or fastening elements on surfaces of construction objects in the field of road traffic which method comprises positioning the element to be attached on the surface on which it is to be attached and liquefying the element by.