Furigana is アウトバーン (autoban). I can't use another word because the author used this word in the original Japanese version. I have no idea why the author use this word, but as a translator, I have to be faithful to the original.
I already translated all of them to Vietnamese, and I'm reluctant to translate it again because the official english translation is available. I'll think about it later, for now I'll focus on the Final Arc.