During the 1930s, the first two motorways were built across the Land, the A4 motorway as an important east-west connection in central Germany and the main link between Berlin and south-west Germany, and the A9 motorway as the main north-south route in eastern Germany, connecting Berlin with Munich. The A4 runs from Frankfurt in Hesse via Eisenach, Gotha, Erfurt, Weimar, Jena and Gera to Dresden in Saxony, connecting Thuringia's most important cities. At Hermsdorf junction it is connected with the A9. Both highways were widened from four to six lanes (three each way) after 1990, including some extensive re-routing in the Eisenach and Jena areas. Furthermore, three new motorways were built during the 1990s and 2000s. The A71 crosses the Land in southwest-northeast direction, connecting Würzburg in Bavaria via Meiningen, Suhl, Ilmenau, Arnstadt, Erfurt and Sömmerda with Sangerhausen and Halle in Saxony-Anhalt. The crossing of the Thuringian Forest by the A71 has been one of Germany's most expensive motorway segments with various tunnels (including Germany's longest road tunnel, the Rennsteig Tunnel) and large bridges. The A73 starts at the A71 south of Erfurt in Suhl and runs south towards Nuremberg in Bavaria. The A38 is another west-east connection in the north of Thuringia running from Göttingen in Lower Saxony via Heiligenstadt and Nordhausen to Leipzig in Saxony. Furthermore, there is a dense network of federal highways complementing the motorway network. The upgrading of federal highways is prioritised in the federal trunk road programme 2015 (Bundesverkehrswegeplan 2015). Envisaged projects include upgrades of the B247 from Gotha to Leinefelde to improve Mühlhausen's connection to the national road network, the B19 from Eisenach to Meiningen to improve access to Bad Salzungen and Schmalkalden, and the B88 and B281 for strengthening the Saalfeld/Rudolstadt region.