The low-speed maneuverability of a long vehicle is greatly improved when the vehicle is broken down into several short units that articulate with respect to one another. Such multiple-articulated vehicles have, however, a tendency to exhibit poor directional stability and low levels of rollover immunity during transient maneuvers executed at highway speeds. A model which can be used to simulate the directional and roll response characteristic of a wide variety of multiple-articulated vehicle combinations is presented in this paper. The model is shown to be a valid descriptor of vehicle behavior and is applied to a series of hypothetical vehicle combinations suitable for transporting liquid cargoes.