Utilization of traffic speed deflectometer for pavement structural evaluations

Traffic Speed Deflectometer (TSD) is primarily capable of evaluating the pavement conditions at the network level with regard to the structural capacities. This paper mainly reviews the utilization of TSD for the pavement structural evaluations. With the Doppler lasers configured in a specific truck, TSD can measure the deflection velocity (slope) at a traffic speed. The measured deflection can be calculated by either area under the curve (AUTC) method or Euler–Bernoulli beam (EB) method. Moreover, the pavement moduli backcalculated by either 3D Move simulation or the Artificial Neural Networks (ANNs) from TSD measurements tend to well correlate those backcalculated from FWD measurements. It is noted that structural capacities derived from TSD measurement were reliable in assessing the pavement conditions. Additionally, the pavement roughness has a significant effect on TSD measurements. Therefore, Traffic Speed Deflectometer has a promising applied prospect in pavement structural evaluations.