The aerodynamic loads, due to transversal wind, can have significant effects on the running safety of railway vehicles since they can modify the running stability of the vehicle with an increasing risk of overturning. The cross wind effects become particularly critical in combination with high running speed, with sudden variations of aerodynamic loads, for instance at an exit from a tunnel, and with cant deficiency, in curve. Moreover, nowadays cross wind effects on railway vehicles are a present problem due to the necessity of defining interoperability standards on this specific topic (TSI). In particular, at the design stage of a new railway vehicle, an aerodynamic study, able to verify the vehicle stability to cross wind action, becomes necessary. This work presents an aerodynamic analysis of cross wind effect on the new AnsaldoBreda EMUV250 train. Two approaches have been used: wind tunnel tests and Computational Fluid Dynamic (CFD) analysis. While the experimental study allows to have an higher confidence in the absolute values of the measured forces, the numerical calculations allow to obtain a more detailed information (pressure field and velocity map of the whole flow,...), very useful to understand the flow field around the vehicle and, as a consequence, to identify the more effective aerodynamic parameters. The aerodynamic coefficients of the first vehicle of the EMUV250 train original version have been measured by wind tunnel tests performed at different angles of wind exposure. Then the CFD analyses have been carried out in order to evaluate the parameters that mostly affect the aerodynamic force. The numerical results have been validated by the experimentally measured aerodynamic coefficients. As a result of the numerical study carried out on the original version of the EMUV250 model, two new vehicle geometries, with improved aerodynamic characteristics in terms of overturning risk, have been designed and tested in the wind tunnel. Starting from these results, through a numerical-experimental methodology, developed during these last years at Mechanical Engineering Department of Politecnico di Milano, the cross wind aerodynamic behaviour of the train can be analyzed in terms of Characteristic Wind Curves, that represent the limit wind speeds leading the railway vehicle to overcome safety limit conditions.