In this study field data was used to demonstrate useful NDT methods and analysis procedures for assessing when and how to repair cracked JCP's. Field data collected from in-service JCP's located throughout southern Michigan was used to accomplish this objective. This paper focuses on descriptions of three NDT methods performed in this study using falling weight deflectometer (FWD) data as well as on the analyses of results obtained from this data. The methods thus considered are: a methodology for determining crack performance parameters; a procedure for backcalculating pavement support and stiffness parameters; and, a technique for assessing void potential near cracks.