Very large wheel loads and lateral forces are frequently caused by short-wavelength track irregularities. These large loads are undesirable, as they have a significant effect on the deterioration of the track material and necessitate additional track maintenance. This study focused on correlation between wheel load, lateral force, axle-box acceleration and track irregularity. First, we analyzed the frequency characteristics of the relationship between wheel loads, lateral forces, axle-box acceleration and track irregularities. Then, we proposed a technique to estimate wheel loads and lateral forces that involves a shortwavelength component using axle-box acceleration and track irregularity waveforms.