66 branches off to Hanau and reaches Bavarian territory. Crossing the Rhön Mountains, pass Schweinfurt (cross with the A 70 to Bayreuth) and Würzburg to the Biebelried intersection, where the A 3 Ruhrgebiet-Frankfurt am Main-Nürnberg-Passau is crossed. This was the southern end of the A7 for a long time. The completion of the south in the 1980s leads past Rothenburg ob der Tauber on the western edge of the Frankenhöhe to the freeway junction Feuchtwangen / Crailsheim (intersection with the A 6 Saarbrücken-Heilbronn-Nuremberg- Waidhaus) and partly Baden-Württemberg area over the Ostalb, for the crossing even two tunnels had to be built, via Aalen to Ulm. At the motorway junction Ulm / Elchingen, the A8 (Luxembourg-Karlsruhe-Stuttgart-Munich-Salzburg) is crossed. South of Ulm it goes through the Illertal parallel to the river back to Bavaria, via Memmingen (cross with the A 96 Lindau Munich) and Kempten (branch to the A 980 to Oberstdorf), over the 2009 completed section through the Reinertshoftunnel to the edge of the foot of the Alps. There, the lane becomes one lane and flows into the border tunnel Füssen to Austria. History The highway replaced as a trunk connection the imperial or federal roads 76, 77, 205 and 4 (Flensburg-Hamburg), 3 (Hamburg-Kassel) and 27 (Göttingen-Würzburg), which in turn went back to medieval precursors. On the route between Flensburg and Hamburg, for example, it follows the historic Ochsenweg and can be described as its successor in terms of its importance as a trade route from Scandinavia to the south. Plans for a highway from Hamburg to the south were made in the framework of the HaFraBa from 1926. This project is considered to be the predecessor of the A7 between Hamburg and the Hattenbacher Dreieck. The first section opened from Göttingen to Bad Hersfeld in 1937. Construction of the section between Bad Hersfeld and Würzburg (Strecke 46) began in 1937 with various bridge structures built however the road wasn't completed before war broke out in 1939 and construction was stopped before being fully abandon in 1940. After World War 2 the route of A7 was altered leaving some of the abandoned bridge structures of Strecke 46 to be preserved as historic monuments. From the 1950s, the highway was built between the A 1 south of Hamburg and the existing part of the A7 near Göttingen and opened in sections. At the A1 the "Horster triangle" was created as the new