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U-Bahn

The U-Bahn has nine lines (U1 to U9) serving Frankfurt and the larger suburbs of Bad Homburg and Oberursel in the north. The trains that run on the U-Bahn are in fact light rail (Stadtbahn) as many lines travel along a track in the middle of the street instead of underground. The minimum service interval is 2.5 minutes, although the usual pattern is that each line runs at 7.5- to 10-minute intervals, which produce between 3- and 5-minute intervals on downtown tracks shared by more than one line.