A system to detect damages at expansion joints of highways has been developed. It has been
observed during highway inspection works, that an experienced inspector is able to identify damaged joints
while performing routine patrol by hearing the sound released by the joint when the patrol car passes through
it. Based on this fact, trials were made to model the abilities of the experienced inspector through the development
of an expert system. Acoustic measurements of sounds released by expansion joints through equipment
mounted inside and outside of a vehicle travelling over the joints were carried out. From the measurement
results it was found that the signals have some characteristics frequency bands. These bands were
analyzed through different methods, such as partial overall, partial overall product and 1/3 octave band. The
obtained results provided means to start the development of a detection system.