Three years of high speed deflectograph measurements of the Danish state road network

The Danish High Speed Deflectograph (HSD) is an advanced measuring vehicle that uses laser technology to scan the network with regard to bearing capacity. It operates at traffic speed, at a maximum of 80 km/h, applying a 10 ton axle load on the pavement surface. In 2005, 2006 and 2007 the Danish state road network of approximately 1600 km was surveyed with the HSD. The result is continuous values of the structural curvature index SCI(300), providing a remarkable overview of the structural condition of the network. The paper contains comparisons between measurements conducted through the three years. Looking deeper at individual road sections, the possible causes of observed changes from one year to the next will be investigated and discussed.