Destructive testing by definition disturbs the underlying pavement layers and this disturbance can have an adverse effect on subsequent performance of the pavement.
Laboratory testing of materials that have been removed from the pavement cannot accurately reproduce the confining support offered by surrounding material in the in-situ pavement. There is also the problem of scaled testing of relatively small diameter samples of material.
NDT tests are relatively quick and inexpensive. In addition, there is almost no disturbance to traffic using the facility.