Driving simulators are used to conduct experiments on driver behavior, road design, and vehicle characteristics, etc. The results of the experiments often depend on traffic conditions. One example is the evaluation of cellular phones and how they affect driving behavior. It is clear that the ability to use phones when driving depends on traffic intensity and composition, and that realistic experiments in driving simulators must therefore include surrounding traffic. This paper describes a model that generates and simulates surrounding rural road traffic for a driving simulator. The model generates a traffic stream, corresponding to a given target flow and simulates realistic interactions between vehicles. The model is built on established techniques for time-driven microsimulation of traffic. The model only considers the closest neighborhood of the driving simulator vehicle. This neighborhood is divided into one inner region and two outer regions. Vehicles in the inner region are simulated according to advanced behavioral models while vehicles in the outer regions are updated according to a less time-consuming model. The paper also discusses calibration and validation of the model and the problem of combining stochastic traffic and driving simulator scenarios.