Which is the second-longest subway line in Hamburg, and which of the two similarly long lines, the U2 and the U3, is actually longer?

When talking about the subway in Hamburg, the longest line is immediately obvious. The U1 is far and away the longest and is even the longest subway line in Germany. That’s exactly why the real interesting question is often overlooked: Which line comes next?

The U4 can be left out right away. At 13.318 kilometers, it is significantly shorter and doesn’t play a role in this comparison. That leaves the two lines that are actually much closer in length than many might think: the U2 and the U3.

And this is where it gets interesting. Unlike the U1, these two lines are relatively close to each other. So this isn’t about a huge gap—it’s a much tighter race.

The U2 has a total length of 24.534 kilometers, while the U3 comes in at 20.681 kilometers. That makes the U2 the second-longest subway line in Hamburg, with a lead of around four kilometers.

Even though this difference looks clear on paper, both lines often feel similarly “large” in everyday use. This is mainly due to their structure. The U3 runs as a ring line through central urban areas, making it highly present. The U2, on the other hand, covers longer stretches that are sometimes less in direct focus.

That’s exactly why many people don’t necessarily confuse them, but rather ask: which one is actually longer? And this close gap makes the topic interesting, because both lines are much closer to each other than to the U1.

In the end, the ranking is clear: U1 in first place by a large margin, followed by U2, and then U3.

Did you expect the U2 to be longer than the U3? Or did you assume they were about the same? Which line do you use more often in everyday life—U2 or U3? Does one of them feel noticeably longer to you?

Source: Wikiolo – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=127913563