The evaluation of different inputmodalities is a conventional question in usability experiments. Meanwhile a multiplicity of alternatives (keyboards, touch, handwriting, turn push knobs etc.) for most different employment scenarios exists. Nowadays touch-screens are not only input devices for mobile human-computer-interaction, but they are spread over many different professional applications, like machinery, industrial workplaces and also in-vehicle applications. The suitability of a touch screen for in-car human-machineinteraction was tested in two experimental studies at the Chair in Ergonomics, Technische Universitaet Muenchen.