Abstract: An automated guided vehicle includes a body, at least one driver wheel for propelling the body along a surface, at least one steered wheel for directing the body with respect to the surface and a body-based inertial navigation system. The inertial navigation system senses actual movement of the body in at least three degrees of freedom. Such sensing is accomplished notwithstanding the presence of side slippage of the vehicle. This can be embodied in an automated guided vehicle having a ground track sensor which continuously senses relative movement of the vehicle with respect to the surface being traversed in order to determine an actual velocity vector of the vehicle. The ground track sensor may physically contact the surface in order to sense the relative movement or may be a non-contact sensor. The disclosed navigation system is especially useful with tugger automated guided vehicles.