Abstract: A device and method for monitoring conditions associated with pavement deterioration are disclosed. Conditions such as voids or loss of support under a rigid pavement, moisture infiltration in asphalt concrete pavement, fine cracking in pavements, delamination of overlays, and aging of asphalt may be measured according to the present invention. These pavement conditions are detected by estimating Young's and shear moduli in the pavement, base, and subgrade from the following wave propagation measurements: Impact Echo; Impulse Response; Spectral Analysis of Surface Waves; Ultrasonic Surface Wave; and Ultrasonic Body Wave Velocity. The pavement response produced by high- and low-frequency pneumatic hammers on five accelerometers and three geophones is recorded. A computer controls data acquisition, instrument control, and interpretation; measurements and interpretations are reported in both screen and database formats.