This paper aims to draw conclusions about the complementarity of two Non-Destructive Testing (NDT) techniques, Ground-Penetrating Radar (GPR) and Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR), in the detection of pavement failures. Regarding the MT-InSAR technique, two Persistent Scatterer Interferometry (PSI) cases were carried out using Sentinel 1A/B images with different orbital directions and temporal periods. The GPR survey was conducted with a ground-coupled antenna of 500 MHz. The results produced showed that the MT-InSAR technique allowed to highlight specific areas of the pavement under investigation, most certainly associated with structural changes. On the other hand, the GPR method allowed to detect different types of subsurface failures, which showed a good agreement with the scatters obtained from the MT-InSAR.