This article shows the results obtained during the implementation of a portable diagnosis system to the maintenance the complex technical objects. As an example, the procedures for testing the behaviour of passenger vehicles and the fixed track of an underground train were proposed, which allowed for the assessment of such aspects as: safety, comfort and technical condition of the track-vehicle junction. The reports given in this evaluation allowed the identification and the arrangement of the track sections according to its technical condition, relating thus the track and vehicle condition parameters to the estimators connected with the passenger vehicles dynamics.