|Downgraded to B 45|
|Length:||22 km (14 mi)|
It was constructed from 1974 to 1979 and led south from the Hanau exit of the A 3. It went through Rodgau and ended at Dieburg, where the Autobahn connected to the A 680 leading westward to Darmstadt.
The Autobahn was downgraded to a Bundesstraße (Bundesstraße 45) in the 80s. Only the signs were changed though - the road, equipped with parking fields and hard shoulders, remained the same. In the 90s the road was continued northward, which turned the Hanau exit into a true interchange and removed the roundabout that used to be there. The continuation to the north, leading through the city of Hanau, is now called the Bundesstraße 43a.