This study deals with the pavement roughness characteristics that affect pavement-heavy vehicle interaction. Dynamic vehicle response data from two sources were analyzed, namely experimental data obtained with the instrumented vehicle developed by the National Research Council of Canada (NRCC) and simulated data obtained with a quarter-vehicle simulation. It was found that the vehicle response parameter of interest in this interaction is the sprung mass vehicle acceleration because it relates to both pavement/vehicle damage as well as to ride quality/cargo damage. The sprung mass vertical acceleration transfer function showed a distinct sensitivity to a pavement roughness excitation frequency of 3.5 Hz. A pavement roughness statistic was proposed based on the vertical sprung acceleration of the sprung mass. It is calculated by multiplying the spectral density of the roughness profile by the square of a reference transfer function and integrating the result. This procedure was implemented into a PC-based computer software program called TRRI (Truck Response to Roughness Index).