Where does “Reichsautobahn” come from?

Reichsautobahn (German) comes from German Autobahn, from German Auto, from German automobil, from Spanish automóvil, from Russian автомоби́ль, from French automobile, from French auto-, from Ancient Greek αὐτο- — Postpositional intensifying particle: indeed, at any rate, in fact.

Ancestry of “Reichsautobahn”, step by step

Reichsautobahn traces back through two separate lines of ancestry.

via German Autobahn

StepLanguageWordMeaning
1GermanAutobahnA class of road built to freeway standards,...
2GermanAutocar
3Germanautomobilautomobile
4Spanishautomóvilautomobile
5Russianавтомоби́льcar, automobile, motorcar
6Frenchautomobileautomotive; automobile
7Frenchauto-auto- regarding oneself
8Ancient Greekαὐτο-self-
9Ancient Greekαὐτόςαὐτή f, αὐτό n; "first/second declension";...
10Proto-Indo-Europeanh₂ewaway from, off; again
11Proto-Indo-EuropeanǵʰePostpositional intensifying particle: indeed, at any rate, in fact

via German reich

StepLanguageWordMeaning
1Germanreichrich; singular imperative of reichen
2Middle High Germanrīcherich
3Old High Germanrīhhirich, mighty; power, might, empire; realm
4Proto-West Germanicrīkīmighty, powerful; rich; kingdom, realm
5Proto-Germanicrīkijazkingly, royal, noble; mighty, powerful; rich
6Proto-Germanicrīksking, ruler
7Proto-Celticrīxsking
8Proto-Indo-Europeanh₃rḗǵsking, ruler
9Proto-Indo-Europeanh₃reǵ-to straighten, to right oneself; right; just
Every word from Proto-Indo-European ǵʰe