Traffic speed deflectometer measurements at the Aurora instrumented road test site

Abstract

The results from a comprehensive set of validation measurements of the Traffic <br/>Speed Deflectometer (TSD) are presented. The measurements took place at the Aurora instrumented road test site in Muonio, Finnish Lapland, at a range of different driving speeds and road temperatures. The ability of the TSD to accurately measure pavement surface response, was validated by comparing the TSD measurements to measurements by in-situ displacement transducers. In addition, a linear viscoelastic back-calculation algorithm was applied to the <br/>TSD measurements to produce estimates of stresses and strains inside the pavement structure. These estimates were compared to measurements by in-situ transducers at the Aurora test site. The tests revealed an excellent agreement between the surface responses measured by the two <br/>systems, and a good agreement between the strains predicted from TSD measurements and the strains measured by in-situ transducers. As expected, the back-calculated moduli of the asphalt were found to increase with driving speed and decrease with temperature.