It was downgraded to a state highway (German: Bundesstrasse) in order to let the Nazi propaganda proclaim that the Reichsautobahn Frankfurt-Darmstadt was the first ever built in Germany.
In 1926, a private association proposed a highway from Hamburg via Frankfurt to Basel (HaFraBa) - these plans were stopped in the Reichstag by a coalition of Communists and Nazis.
The HaFraBa was renamed "Gesellschaft zur Vorbereitung der Reichsautobahnen", which translates "Company for the preparation of the Reich highways".
The part between Frankfurt and Darmstadt with a length of about 25 km was the first and still is Germany's longest Autobahn section with 8 lanes.
A 10 km (6.2 mi) section of A 5 south of Frankfurt were installed with overhead lines for hybrid trucks to use starting in May 2019.