Plans for a European motorway connection from Berlin to Rome were already developed from 1927 by a private MüLeiBerl (Munich-Leipzig-Berlin) company.

It was inaugurated in sections, beginning in 1936 with the Strecke 16 between what is today's Schkeuditz interchange (present-day A 9 and A 14) near Leipzig and Bad Berneck im Fichtelgebirge, 164 kilometres (102 mi) in length.

[1] The U.S. Army Europe under Lucius D. Clay considered a tank offensive to forcibly reopen the route, but chose not to implement the plan since it had no guaranteed chance of success and would lead to World War III if the Group of Soviet Forces in Germany chose to resist.

A section in Thuringia between Schleiz and the Rodaborn rest area even was a cobblestone road, later paved over by the East German authorities until being replaced by concrete in the 1980s.

After reunification, the continuous six-lane expansion of the A 9 from the Potsdam junction to the Nuremberg interchange was tackled as an important transport project German unit No.

As part of the six-lane expansion, the new route was relocated in some sections, as the old road has gradients of sometimes over seven percent and tight curve radii.

For example, in the area of Münchberg south of Hof a viaduct was built to avoid the guidance of the highway through a fog valley, especially because in this section on 19 October 1990 a heavy pile-up with ten dead and numerous seriously injured had occurred.

This very stressful condition for the residents was eliminated with the new track construction; Today, the highway runs east of the village.

The 120 million DM expensive conversion between the junctions Bayreuth-North and -Süd, which included a 320 -meter-long enclosure and noise barriers, dragged itself into the year 2006.

Another reason for the delay was the fact that in terms of financing new Tried ways and private investors were searched by tender, which should refinance on the truck toll (so-called A-model).

According to the announcement of 4 August 2011, the consortium A9SixLanes from the companies VINCI Concessions (47.5%), BAM PPP (47.5%) and Reinhold Meister GmbH (5%) was awarded the contract for the expansion.

It had been opened in 1928 as a tourist restaurant for the citizens of Triptis and was in 1936 with the completion of the Reichsautobahn to the first motorway service area in Germany.

Also two resting places in Bavaria had to give way to the six-lane extension; on the one hand Sophienberg south of Bayreuth and Hienberg north of Nuremberg on the same mountain.

On 26 January 2015 German transport minister Alexander Dobrindt announced plans to outfit an as yet undesignated section of the A9 in Bavaria as a test track for autonomous cars.

South of exit 11, Dessau-South, nearly ten kilometers of the roadbed — roughly from Thurland southwards to just north of the B 183 (ex-B 186) interchange (exit 12 for Bitterfeld/Wolfen of the modern A9 roadbed) — were upgraded with a paved-over median to become the "Dessauer Rennstrecke" (Dessau Racetrack), a 25-meter (82 ft) wide high-speed track intended for races and record attempts, such as by Rudolf Caracciola in 1938/39, Goldie Gardner in 1939 or those by Hans Stuck with the Mercedes-Benz T80 land speed record car, intended to start in January 1940 - the Rennstrecke segment itself had even been marked out on road maps as early as 1938.

[5] With its pillarless bridges and no interchange exits before 1945, but especially with the straight alignment and the broad concrete surface without a distinct median, it was also intended to function as an auxiliary airfield in World War II.

On 30 June 2004 Germany's oldest autobahn inn, Rodaborn near Triptis, was closed due to the upgrading of the old two-lane to the modern three-lane profile.

Though the connection to the adjacent autobahn parking lot is cut off by a fence, Rodaborn still is a popular stop for motorway travellers.

Between 1945 and 1966 the A 9 was interrupted at the inner German border between Bavaria and Thuringia since an arch of the bridge had been blown up by retiring Wehrmacht forces near the end of the war.

Exit 45, Weidensees, was called "Veldensteiner Forst" until the 1970s and was probably built on behalf of Hermann Göring, who had a hunt nearby.

Its equivalent is placed on the median of the A 115 (as the extension of the A 9 into Berlin) near former rest area Dreilinden, north of the former checkpoint Bravo 52°25′05″N 13°11′47″E / 52.41806°N 13.19639°E / 52.41806; 13.19639.