Ingo Maurer is not only known for his unique and humorous lamp collection, but also for light installations in the public space. Ingo Maurer's designs for subway stations in Munich have turned these rather uncomfortable transit spaces and passages by means of light and colour into places with a high quality of living. The stations Westfriedhof, Münchner Freiheit and Marienplatz are popular amongst users and operators, and are now frequently visited by planners from other regions. Ingo Maurer accompanies the urban railway project in Karlsruhe since 2004. The design of Allmann Sattler Wappner Architekten for the city of Karlsruhe provides for connecting the inner city underground with the urban railway. Like a subterranean guideline, the new, uniform design of seven tram stops laid in the underground leads through the inner city of Karlsruhe. These stops refer to their spatial strength and poetry from a restrained design that is in contrast to the visual and acoustic charm density of the overlying pedestrian zone. The cubic void space of the interiors is decisively determined by the shape of the respective civil engineering structures and the specific urban situation. This gives each stop a unique character with a high degree of recognition, which allows conclusions to be drawn about the external conditions. The formally reduced design of the rooms reinforces the individual character of the stops. The concept provides for two room categories, which follow different design principles: in the transfer room with stairs and intermediate floors, the configuration of the civil engineering building is mapped directly and without structural cladding. The transit and waiting area on platform level has a soothing, almost meditative character with leveled colours and bright surfaces. The same materiality of the ceiling, wall and floor reduces and focuses on the important elements of the trams, fonts and signs. Ingo Maurer's impressive lighting design is inspired by these formally reduced interior spaces. The topic of overhead lines and the supposed tangle of wires and cables that runs over railway tracks is the starting point of the light concept. In each of the seven railway stations, wire ropes are stretched across both platforms. One segment consists of six ropes, three of which lie side by side and a row above. On each side of the platform are ten cylindrical light bars on the ropes. Six bars ensure uniform illumination of the platform; the four remaining lights illuminate the ceiling. These cylindrical light bars are placed on top of the wire ropes. While the alignment of the bars is strictly in the direction of train tracks, they seem to float randomly in height. In addition, the waiting passengers are framed at the platform by colored shadows, which follow passengers and eventually may lead to interactions. The visual tension of wire cables and power cables, in their aesthetics, is a reminiscence of the electrification of the railway and the implied belief in progress. Ingo Maurer describes this cabelage as a kind of 'industrial romance' in technology impressed by its visibility and comprehensibility. Electricity is noticeable. The seven metro stations for the Karlsruhe urban railway are under construction.