The Ultra Low Floor tram (ULF) is a low-floor tram operating in Vienna, Austria and Oradea, Romania, with the lowest floor-height of any such vehicle. In contrast to other low-floor trams, the floor in the interior of ULF is at sidewalk height (about 18 cm or 7 inches above the road surface), which makes access to trams easy for passengers in wheelchairs or with baby carriages.
This configuration required a new undercarriage. The axles had to be replaced by a complicated electronic steering of the traction motors. Auxiliary devices are installed largely under the car’s roof.