U3 was Germany’s first fully automatic underground railway line.
Nuremberg’s U3 began commercial operation on 14 June 2008 with driverless trains from its first day. Its automatic train-control system manages movement, braking and other operating functions, while platform monitoring equipment helps detect objects or people on the track. The line’s rolling stock was designed specifically for automatic operation.
U3 was created partly by reusing a central tunnel shared with the older U2. Rather than constructing an entirely separate route through the city centre, planners used automation to increase capacity on the shared section. That made U3 an important test of mixed operation, with automatic U3 trains initially sharing infrastructure with conventionally operated U2 services.
The wording can be misleading because U3 was not Germany’s first railway technology experiment involving automation. It was the first German U-Bahn line to open as a fully automatic, driverless underground line. Nuremberg’s U2 was converted to full automatic operation later, with the conversion completed in January 2010.