U4 (Frankfurt U-Bahn)

U4
Network map
Overview
System	Frankfurt U-Bahn
Stations	15
Services	04:08 AM – 01:08 AM Every 5 min. (RH) Every 7/8 min. (MD) Every 15 min. (N)
Operation
Opened	1974
Owner	RMV
Operator(s)	Stadtwerke Frankfurt
Rolling stock	Siemens–Duewag U2, U3-Triebwagen
Technical
Line length	11.3 km (7.0 mi) 24 minutes (avg.)
Operating speed	28.3 km/h (17.6 mph) average
Average inter-station distance	753 m (2,470 ft)

The U4 is a line on the Frankfurt U-Bahn. At the time of the line's inauguration in 1980, it ran from the central railway station to the Konstablerwache and then continued along the Berger Straße all the way up to Seckbacher Landstraße in Bornheim, making it the first line to run entirely underground over its total length. In 2001, the U4 was extended from the central railway station to Bockenheimer Warte, with an additional stop at the Frankfurt Trade Fair along the way. In 2008, some of the trains started continuing past Seckbacher Landstraße to Schäfflestraße and then overground to Enkheim together with the U7.

U4 at Bockenheimer Warte station, bound for Seckbacher Landstraße