Track geometry quality has an important influence on the dynamic behaviour of the vehicles. Control of track geometry during the maintenance process and for the vehicle assessment (homologation) is necessary. Within the project, DYNOTRAIN methods for describing and assessing track geometry have been studied. Data from a comprehensive test campaign have been used to measure the effectiveness of different track geometry assessment methods. The vehicle behaviour has been studied by a multiple regression model with varying track geometry description methods. It had been shown that it is essential to include track geometry in the vehicle assessment process in a proper way. Depending on the assessment quantity and the vehicle type, the mostly used method in Europe (standard deviation in wavelength range 3–25 m) allows in combination with speed, cant deficiency and curvature the explanation of 20–80% of the total variation of the vehicle reaction. Other methods and ‘new’alternative methods intended to model a typical vehicle behaviour mostly give no or only a small improvement.