Bundesautobahn 71

 is an Autobahn in Germany. It connects the A 38 and Erfurt to the A 70 near Schweinfurt. A further northern extension to the A 14 near Plötzkau has been proposed by the state government of Sachsen-Anhalt.
Construction on the A 71, supervised by DEGES, began in 1996, most parts were being opened by December 2005. The project was completed in September 2015. The section through the Thuringian Forest was the most expensive road ever built in Germany with an average cost of . This section includes the "Rennsteig Tunnel" which is the longest road tunnel in Germany at and is called "Thüringer wald Autobahn" (Thuringian Forest Motorway).
Exit list.
 
Characteristics.
Buildings at Thuringian forest.
While crossing the Thuringian Forest are a lot of large engineering works needed, the most notable are listed in the table below.