First results have been obtained with the developed method for public transport (PT) network design. Nearly shortest PT-lines are suited for high demand relations. For lower demanded relations circuitous PT-lines with still acceptable headways are advantageous. It turned out that a third class of PT-lines should be considered, connecting important transfer nodes with each other. This class of PT-lines shows similar forms as the magnetic streamlines of the field, connecting several magnetic poles. Bernhard Alt