ABSTRACT
The Traffic Speed Deflectometer (TSD) measures surface deflection slopes along the midline of the rear right dual tires. Full utility of the TSD device can be achieved in Pavement Management System (PMS) application when pavement surface deflections are computed from measured deflection slopes using deflection algorithms. Several algorithms have been proposed to compute surface deflections from slope measurements, including the TSD algorithm, AUTC-PCHIP, AUTC-Piecewise Liner, and this study attempts to compare and contrast the deflections and deflection indices derived using the different algorithms along with that from 3D-Move analytical program. The 3D-Move presents a realistic method to compute pavement structural response under the TSD loading. When the measured TSD slope data contains minimal noise, all deflection algorithms estimated similar pavement responses. However, in the case of significant noise in the measured data; AUTC algorithms yield irregular slope curve since the curves are forced to pass through all data points. Using a filtering method to screen and exclude or adjust anomalous slopes before applying deflection algorithms could resolve this issue.
