A driving assistance device for the semi-autonomous and fully autonomous guidance of a transportation vehicle, wherein the driving assistance device calculates potential return trajectories for the respective return of a transportation vehicle from an initial condition, which deviates from a predefined target trajectory, to the target trajectory, wherein each return trajectory satisfies a respective predetermined driving dynamics profile which defines a permissible value range of a total acceleration, and to which a respective degree of autonomy is assigned. The driving assistance device selects the return trajectories which satisfy a selection criterion with at least one boundary condition as suitable return trajectories, and from the suitable return trajectories identifies that whose driving dynamics profile has a minimum degree of autonomy as the suitable return trajectory and intervenes in the guidance of the transportation vehicle based on the degree of autonomy of the driving dynamics profile of the selected suitable return trajectory.