Welcome to the Autobahn Information Site
The German autobahns are famous because they are some of the few public roads in the world without blanket speed limits for cars and motorcycles. Lack of blanket speed limits does not appear to negatively impact the road safety of autobahns compared with motorways in other countries; motorways are safer than other road types. Perhaps this is in part because traffic can be heavy enough to restrict speeds to little above the typical motorway speeds found elsewhere, or due to reducing the exhaustion of the drivers by shortening their travelling times.
The German Autobahn network is approximately 12.000 kilometers long. The third in the world after United States and China. Also take in consideration the land area of USA is more than 25 times Germany. China is about the same size as United States.
Top 3 Highway Networks
Unites States: 74 950 km (46 570 mi)
China: 43 000 km (26 720 mi)
Germany: 12 174 km (7 565 mi)
The numbers above is a little misleading because the differences between European and American standards in what classifies a Motorway. In United States there are many names for "Autobahn" (Highway, Interstate, Freeway, Turnpike etc.). Motorway-like roads in USA which allow pedestrians and bicycles would not be classified as Motorway in Europe, but are counted for in the statistics above.

This section of Autobahn near the Czech border probably have speed limits
Music for Meditation.