In a context of increasing interoperability, several high speed trains, such as ICE, TGV, ETR 500, are likely to run on the same tracks, whereas they have been originally designed for specific and different railway networks. Due to different mechanical properties and structures, the dynamic behaviors, the aggressiveness of the vehicle on the track and the probabilities of exceeding security and comfort thresholds will be very different from one train to an other. These maintenance, certification and comfort criteria depend on the dynamic interaction between the vehicle and the railway track and in particularly on the contact loads between the wheels and the rail, which are very hard to evaluate experimentally. Moreover, the track-vehicle system being strongly non-linear, this dynamic interaction has to be analyzed not only on a few track portions but on the whole realm of possibilities of running conditions that the train is bound to be confronted to during its life cycle. The idea of this paper is therefore to show to what extent this influence of the track geometry variability on the train dynamics can be analyzed from the coupling of a deter-ministic multibody modeling of the train with a track geometry stochastic modeling, which has been identified and validated from experimental data.