[detaro]

Starting with 5th grade, primary school has 4 years (or 6 in 2 states, and possibly different numbers in experimental cases).

And while switching between the tracks indeed is difficult, it is possible to either gain the Abitur after going to one of the "lower" levels by taking additional years of schooling, or start at uni (especially universities of applied science) without it all. The article you linked gives the (to me surprising, I wouldn't have expected the numbers to be that high) statistic of

> The most traditional route has always been graduation from a Gymnasium with the Abitur; however this has become less common over time. As of 2008, less than half of university freshmen in some German states had graduated from a Gymnasium. Even in Bavaria (a state with a policy of strengthening the Gymnasium) only 56 percent of freshmen had graduated from a Gymnasium.

That said, this early split certainly is a heavily debated topic and in many cases likely is not optimal.