This article presents the instrumented dynamic penetrometer Panda 3®, the principle function and development to characterize the geomechanical behavior of the different layers forming the railway track structure. Initially, laboratory tests were launched in a calibration chamber to test the repeatability and reliability of measurements. The test material included two types of soil (Allier sand and Laschamps clay) compacted at different density. The results were conclusive in qualitative and quantitative terms. Subsequently, a summary of results obtained in various test campaigns performed on three railway sites is also presented, in order to assess a possible similarity of results obtained with the new technique to those obtained from conventional geotechnical and geophysical tests.