The in-house computer program DIFF has been applied to investigate dynamic vehicle-track interaction at high vehicle speeds. A structural dynamics model of a flexible wheelset that fully accounts for the inertial effects due to wheel rotation has been implemented. By formulating the equations of motion using Eulerian coordinates, difficulties to incorporate the interaction forces at the wheel-rail contact are avoided. The importance of considering the inertial effects due to rotation in the modelling of the wheelset has been assessed for different load cases. For a rotating wheel, when viewed from the position of the wheel-rail contact, the receptance peak at each wheelset resonance of multiplicity two splits into two peaks. According to the Campbell diagram for a given vehicle speed, it is observed that the splitting of resonance frequencies increases with the number of nodal diameters of the wheel eigenmodes. When using either a rotating or a non-rotating flexible wheelset model, this study has shown that if the wheelset is excited at a frequency where two different mode shapes, due to the wheel rotation, have coinciding resonance frequencies, significant differences in the amplitude and phase of the calculated vertical and longitudinal wheel-rail contact forces may appear. This implies that it is important to consider the rotational effects in order to accurately capture the wheelset dynamics at high vehicle speeds and excitation frequencies. Further work is required in order to more thoroughly investigate this topic. The frequency content of the vertical wheel rail contact force is dependent on the type of excitation. In this frequency range, the Fourier spectrum of the vertical contact force indicated a large influence of wheelset structural flexibility. However, the effect from accounting for wheel rotation in the wheelset model was negligible. In the current work, large differences were found if instead a broad-band excitation with significant components in the high-frequency range (above 1.5 kHz) was introduced. The influence of structural flexibility was observed for frequencies corresponding to the radial wheel modes with two or three nodal diameters at about 1725 and 2400 Hz. At and around these frequencies, the effect of wheel rotation was visible in the contact force spectra. For the case with a broad-band excitation, both calculated and measured levels of vertical contact force showed a significant influence of the dynamics of the vehicle-track system in a frequency range below 1.5 kHz. This emphasises the importance that the simulation model correctly captures the dynamic behaviour in this frequency range in order to obtain accurate results. Differences in the spectral content of the contact force calculated at different vehicle speeds were concentrated to the frequency ranges corresponding to the radial wheel modes with two or three nodal diameters. Good agreement was found between the calculated and measured vertical contact forces in the frequency range below about 1.5 kHz.