Pavement Condition Measurement at High Velocity using a TSD

The aim of this paper is to present the latest developments in the use of an instrumented vehicle called the Traffic Speed Deflectometer (TSD). A large axle load is applied to the pavement under the TSD . The deflection caused by this axle load is measured using several Doppler lasers. In the first step, the velocity of the deflection of the pavement is measured which can be shown to be proportional to the slope of the de- formed profile . The pavement deflection is calculated in the second step using an integration model . A Wi n- kler model is used to simulate the pavement behavio ur under the axle load and the TSD is represented as a half-car model . The TSD is shown to be an effective tool for pavement damage detection.