The load-bearing capacity of the existing pavement structure is determined on the basis of deflection measurements. Measurement of deflection (deflection) of the pavement structure is performed with a deflectometer with falling load FWD.

The measurement is performed at measuring points (cross-sections), usually in the direction of the right wheel, observing in the direction of movement, on each traffic lane separately, at the appropriate distance (measuring interval is usually 50 m). 3 measurements (strokes) are performed at each measuring point. The measurement is performed using the appropriate dynamic force that is transmitted to the road via a circular plate with a diameter of 300 mm. Deflections are measured with geophones placed in the center of the circular plate and at distances of 200, 300, 450, 600, 900, 1200, 1500 and 1800 mm from the center of the circular plate.