Due to the circuitous horseshoe-shaped route, U3 is not always the fastest public transit option between its stations.

While the original plans of the U-Bahn network to be all called for at least three main trunk lines on their entire dedicated corridors, financial constraints and the decision not to abandon the Tramway network as had been planned at the time the U-Bahn began construction, made it clear after the construction of U2 that a third trunk line would be economical only if the Tram network was abandoned after all.

A political consensus emerged to keep the Tram network, but still expand the U-Bahn system, if a bit slower and more moderately.

The 2011 extension of the northern branch of the U3 led to the - to date - last major permanent shutdown of service on part of the Nuremberg tramway network, as service thru Pirckheimer Straße was shut down (while the rails and overhead wiring remained as a backup in case of closures on other routes) due to the potential of one line "cannibalizing" the ridership of the other.

[4] During the rush hour peak, trains on U3 leave every 3 1/3 minutes (200 seconds) which overlaps with U2 to a 100-second headway between Rathenauplatz and Rothenburger Straße.

The VAG Class G1 currently in use on U1 is capable of both automatic and manual operation and could in the future be used on U3 but isn't as of 2022.