Our company performs diagnostics of road, railroad and pipelines surface and subsoil. In order to determine geotechnical conditions of foundation of linear objects; it is very difficult to reach a compromise between the amount of field investigations and the accuracy of diagnosis of geotechnical conditions. Ground penetrating radar [GPR] technique allows to reduce number of necessary to perform classical geotechnical tests to a minimum. GPR technique is also used to continuously monitor the roadbed and railway trackbed, without affecting traffic flow or train schedules.