The route begins in the southwest of Nuremberg at Röthenbach station, at the western end of a three-track parking and turning system, and continues east along the Schweinauer Hauptstraße under the Main-Danube Canal and the de:Südwesttangente highway (southwestern tangential road) to the station Hohe Marter.

Rothenburger Straße station marks the beginning of the shared trunk line between U2 and U3 and is also served by S1 of the Nuremberg S-Bahn.

The last part of the southern half of the route runs in a curve under the Obere Kanalstraße and then leads in a right arc to the Plärrer station, where the U2 meets the U1.

The Plärrer is an old interchange point for all kinds of transportation and was served by Germany's first railway and at times over a dozen tram lines.

Then the route takes a narrow counter arc under housing development to the station Ziegelstein beneath Fritz Munkert Platz, at whose northern end is another parking and turning system.

The two railway tracks are then merged and run as a single-track tunnel in a westerly direction to the terminus station serving the airport.

Occasionally a train with minor defects or awaiting a later departure will wait on the mostly unused second platform track.

Furthermore, the municipal finances, which had been healthy in the 1960s when the decision to build the subway was taken, were becoming increasingly strained and thus a fully fledged three- or even four-line network seemed to be decades away if it was ever going to happen.

The U2 was finished with a connection to the airport (then slowly but surely coming into its own as a hub for Air Berlin's winter season touristic operations), but to cut costs it was built single track only.

However, by the time this decision was put into practice, the political winds had turned again and Ulrich Maly retook the mayorality for the SPD once more after a single 6 year term by Ludwig Scholz of the CSU.

Another problem is the de:Gemeindeverkehrsfinanzierungsgesetz (municipal traffic financing law or GVFG) which regulates which construction projects get federal and state funding and mandates a so-called "Benefit-Cost Quotient" above 1.0 (i.e. "benefits" exceeding "costs") and an extension to Stein is unlikely to meet that as only the newly built stretch would be taken under consideration.

In addition to linking the airport to the interchange point and relieving the residential areas of bus traffic, such an extension would also offer an interchange between tram line 4 (which is planned to be extended towards Erlangen in the course of the "Stadt-Umland Bahn“ project) and U2 (otherwise only possible at Plärrer station) and relieve the airport of the role as a bus/subway interchange point, that it only gained in the course of the reorganization of bus traffic in the north of Nuremberg in the course of the opening of the tram extension to "am Wegfeld" in 2016.

Including a proposed "Marienberg" station which was already indicated as a possibility in promotional material released during the opening of the extension towards the airport.